Added example for a blog that shows update dates (#8)

* added example for a blog that shows update dates

these exist already in the template for the posts but were left out of
the index pages for a tidier look.

* implemented PR feedback

- fixed typo
- removed  
- replaced "don't edit" warning with message about updates
- added note on updates to README
- fixed indentation

examples/blog-update/.example.yml

@@ -0,0 +1,11 @@
+example:
+  tags:
+    - public        # works without Insiders
+    - blog          # functionality demonstrated
+    - simple        # requires no extra plugins or other magic
+    - customization # shows how to customize the theme
+  authors:
+    alexvoss:
+      name: Alex Voss
+      description: Collaborator
+      avatar: https://github.com/alexvoss.png

examples/blog-update/docs/README.md

@@ -0,0 +1,27 @@
+# A blog with update dates shown
+
+This example shows how to add a small customization that will show
+then blog posts were [updated] on the blog index pages. (The blog page
+template already contains this.)
+
+It shows how to:
+
+- add an update date in addition to the creation date for a post as in [My first post]
+- override the template index pages, so
+  that the [main blog index], the [archive index] and the [categories
+  index] show the update date
+
+**Note**: Please note that when overriding templates you are copying
+part of the code that makes up Material for MkDocs and so need to take
+care when upgrading. The [changelog] contains a note on which
+templates have changed, if any. 
+
+If you have not already set up a blog for your site then please start
+with the [Basic blog] example.
+
+[changelog]: https://squidfunk.github.io/mkdocs-material/changelog/
+[Basic blog]: ../blog-basic
+[My first post]: blog/2023/10/11/my-first-blog-post
+[main blog index]: blog
+[archive index]: blog/archive/2023
+[categories index]: blog/category/meta

examples/blog-update/docs/blog/.authors.yml

@@ -0,0 +1,9 @@
+authors:
+  squidfunk:
+    name: Martin Donath
+    description: Creator
+    avatar: https://github.com/squidfunk.png
+  alexvoss:
+    name: Alex Voss
+    description: Weltenwanderer
+    avatar: https://github.com/alexvoss.png

examples/blog-update/docs/blog/index.md

@@ -0,0 +1,2 @@
+# Blog
+

examples/blog-update/docs/blog/posts/firstpost.md

@@ -0,0 +1,36 @@
+---
+authors: 
+  - alexvoss
+date: 
+  created: 2023-10-11
+  updated: 2023-10-18
+categories:
+  - meta
+---
+
+# My first blog post
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit. Pellentesque nec
+maximus ex. Sed consequat, nulla quis malesuada dapibus, elit metus vehicula
+erat, ut egestas tellus eros at risus. In hac habitasse platea dictumst.
+Phasellus id lacus pulvinar erat consequat pretium. Morbi malesuada arcu mauris
+Nam vel justo sem. Nam placerat purus non varius luctus. Integer pretium leo in
+sem rhoncus, quis gravida orci mollis. Proin id aliquam est. Vivamus in nunc ac
+metus tristique pellentesque. Suspendisse viverra urna in accumsan aliquet.
+
+<!-- more -->
+
+Donec volutpat, elit ac volutpat laoreet, turpis dolor semper nibh, et dictum
+massa ex pulvinar elit. Curabitur commodo sit amet dolor sed mattis. Etiam
+tempor odio eu nisi gravida cursus. Maecenas ante enim, fermentum sit amet
+molestie nec, mollis ac libero. Vivamus sagittis suscipit eros ut luctus.
+
+Nunc vehicula sagittis condimentum. Cras facilisis bibendum lorem et feugiat.
+In auctor accumsan ligula, at consectetur erat commodo quis. Morbi ac nunc
+pharetra, pellentesque risus in, consectetur urna. Nulla id enim facilisis
+arcu tincidunt pulvinar. Vestibulum laoreet risus scelerisque porta congue.
+In velit purus, dictum quis neque nec, molestie viverra risus. Nam pellentesque
+tellus id elit ultricies, vel finibus erat cursus.
+
+Edit: Nam placerat purus non varius luctus. Integer pretium leo in
+sem rhoncus, quis gravida orci mollis. Proin id aliquam est.

examples/blog-update/docs/blog/posts/secondpost.md

@@ -0,0 +1,32 @@
+---
+authors: 
+  - squidfunk
+date: 2023-10-12
+categories:
+  - hello
+---
+
+# A second post
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit. Pellentesque nec
+maximus ex. Sed consequat, nulla quis malesuada dapibus, elit metus vehicula
+erat, ut egestas tellus eros at risus. In hac habitasse platea dictumst.
+Phasellus id lacus pulvinar erat consequat pretium. Morbi malesuada arcu mauris
+Nam vel justo sem. Nam placerat purus non varius luctus. Integer pretium leo in
+sem rhoncus, quis gravida orci mollis. Proin id aliquam est. Vivamus in nunc ac
+metus tristique pellentesque. Suspendisse viverra urna in accumsan aliquet.
+
+<!-- more -->
+
+Donec volutpat, elit ac volutpat laoreet, turpis dolor semper nibh, et dictum
+massa ex pulvinar elit. Curabitur commodo sit amet dolor sed mattis. Etiam
+tempor odio eu nisi gravida cursus. Maecenas ante enim, fermentum sit amet
+molestie nec, mollis ac libero. Vivamus sagittis suscipit eros ut luctus.
+
+Nunc vehicula sagittis condimentum. Cras facilisis bibendum lorem et feugiat.
+In auctor accumsan ligula, at consectetur erat commodo quis. Morbi ac nunc
+pharetra, pellentesque risus in, consectetur urna. Nulla id enim facilisis
+arcu tincidunt pulvinar. Vestibulum laoreet risus scelerisque porta congue.
+In velit purus, dictum quis neque nec, molestie viverra risus. Nam pellentesque
+tellus id elit ultricies, vel finibus erat cursus.
+

examples/blog-update/mkdocs.yml

@@ -0,0 +1,40 @@
+# Copyright (c) 2016-2023 Martin Donath <[email protected]>
+#                         Alex Voss <[email protected]>
+
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to
+# deal in the Software without restriction, including without limitation the
+# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+# sell copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+# IN THE SOFTWARE.
+
+# -----------------------------------------------------------------------------
+# Recommended: set up configuration validation, see https://t.ly/xpZXU
+# -----------------------------------------------------------------------------
+
+# Project information
+site_name: Blog that shows post updates
+
+# Theme
+theme:
+  name: material
+  custom_dir: overrides
+
+watch:
+  - overrides
+
+# Plugins
+plugins:
+  - search
+  - blog

examples/blog-update/overrides/partials/post.html

@@ -0,0 +1,70 @@
+{#-
+  Remember to check the changelog when updating Material for MkDocs. If the
+  template has changed it is generally a good idea to apply the customization
+  to the new one instead of depending on an old template, which may cause
+  problems downstream.
+-#}
+<article class="md-post md-post--excerpt">
+  <header class="md-post__header">
+    {% if post.authors %}
+      <nav class="md-post__authors md-typeset">
+        {% for author in post.authors %}
+          <span class="md-author">
+            <img src="{{ author.avatar }}" alt="{{ author.name }}">
+          </span>
+        {% endfor %}
+      </nav>
+    {% endif %}
+    <div class="md-post__meta md-meta">
+      <ul class="md-meta__list">
+        <li class="md-meta__item">
+          <time datetime="{{ post.config.date.created }}">
+            {{- post.config.date.created | date -}}
+          </time>
+          <!-- start customization -->
+          {% if post.config.date.updated %}
+            <time datetime="{{ post.config.date.updated }}">
+              ({{ post.config.date.updated | date }})
+            </time>
+          {% endif %}
+          <!-- end customization -->
+          {#- Collapse whitespace -#}
+        </li>
+        {% if post.categories %}
+          <li class="md-meta__item">
+            {{ lang.t("blog.categories.in") }}
+            {% for category in post.categories %}
+              <a href="{{ category.url | url }}" class="md-meta__link">
+                {{- category.title -}}
+              </a>
+              {%- if loop.revindex > 1 %}, {% endif -%}
+            {% endfor -%}
+          </li>
+        {% endif %}
+        {% if post.config.readtime %}
+          {% set time = post.config.readtime %}
+          <li class="md-meta__item">
+            {% if time == 1 %}
+              {{ lang.t("readtime.one") }}
+            {% else %}
+              {{ lang.t("readtime.other") | replace("#", time) }}
+            {% endif %}
+          </li>
+        {% endif %}
+      </ul>
+      {% if post.config.draft %}
+        <span class="md-draft">
+          {{ lang.t("blog.draft") }}
+        </span>
+      {% endif %}
+    </div>
+  </header>
+  <div class="md-post__content md-typeset">
+    {{ post.content }}
+    <nav class="md-post__action">
+      <a href="{{ post.url | url }}">
+        {{ lang.t("blog.continue") }}
+      </a>
+    </nav>
+  </div>
+</article>

examples/blog-update/requirements.txt

@@ -0,0 +1,21 @@
+# Copyright (c) 2016-2023 Martin Donath <[email protected]>
+
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to
+# deal in the Software without restriction, including without limitation the
+# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+# sell copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+# IN THE SOFTWARE.
+
+mkdocs-material