docs: customize changelog template to include commit message body

changelog-template-commit.hbs

@@ -0,0 +1,48 @@
+{{!--
+  Copy of https://github.com/conventional-changelog/conventional-changelog/blob/master/packages/conventional-changelog-conventionalcommits/templates/commit.hbs
+
+  The following have been replaced:
+
+  - `commitUrlFormat` with `{{@root.host}}/{{@root.owner}}/{{@root.repository}}/commit/{{hash}})`
+  - `issueUrlFormat` with `{{@root.host}}/{{@root.owner}}/{{@root.repository}}/issues/{{this.id}}`
+
+  As they won't be replaced when overriding the commitPartial
+--}}
+*{{#if scope}} **{{scope}}:**
+{{~/if}} {{#if subject}}
+  {{~subject}}
+{{~else}}
+  {{~header}}
+{{~/if}}
+
+{{~!-- commit link --}}{{~#if hash}} {{#if @root.linkReferences~}}
+  ([{{shortHash}}]({{@root.host}}/{{@root.owner}}/{{@root.repository}}/commit/{{hash}}))
+{{~else}}
+  {{~shortHash}}
+{{~/if}}{{~/if}}
+
+{{~!-- commit references --}}
+{{~#if references~}}
+  , closes
+  {{~#each references}} {{#if @root.linkReferences~}}
+    [
+    {{~#if this.owner}}
+      {{~this.owner}}/
+    {{~/if}}
+    {{~this.repository}}{{this.prefix}}{{this.issue}}]({{@root.host}}/{{@root.owner}}/{{@root.repository}}/issues/{{this.id}})
+  {{~else}}
+    {{~#if this.owner}}
+      {{~this.owner}}/
+    {{~/if}}
+    {{~this.repository}}{{this.prefix}}{{this.issue}}
+  {{~/if}}{{/each}}
+{{~/if}}
+{{!-- End of copy --}}
+
+{{!-- Start of custom additions --}}
+{{#each bodyLines}}
+
+  {{this}}
+{{/each}}{{#each notes}}
+  **BREAKING CHANGE**: {{text}}
+{{/each}}

release.config.js

@@ -1,3 +1,20 @@
+import { readFileSync } from 'node:fs'
+
+const commitPartial = readFileSync('./changelog-template-commit.hbs', { encoding: 'utf-8' })
+
+/**
+ * Adds the commit body line by line so I can add it with the correct indentation in `changelog-template-commit.hbs`.
+ */
+function finalizeContext(context) {
+	for (const commitGroup of context.commitGroups) {
+		for (const commit of commitGroup.commits) {
+			commit.bodyLines = commit.body?.split('\n').filter((line) => line !== '') ?? []
+		}
+	}
+
+	return context
+}
+
 /** @type {import('semantic-release').Options} */ const options = {
 	branches: [
 		'main',
@@ -11,6 +28,10 @@
 		// https://github.com/semantic-release/release-notes-generator
 		['@semantic-release/release-notes-generator', {
 			preset: 'conventionalcommits',
+			writerOpts: {
+				commitPartial,
+				finalizeContext,
+			},
 		}],
 
 		// This creates/updates the CHANGELOG.md file.