Node revamp: Controllers Lesson

[fcasibu]

Because

To add a new lesson about Controllers in the MVC pattern for the node revamp

This PR

• Adds new lesson to nodeJS/express/controllers.md

Issue

Closes #27615

Additional Information

Pull Request Requirements

• I have thoroughly read and understand The Odin Project Contributing Guide
• The title of this PR follows the location of change: brief description of change format, e.g. Intro to HTML and CSS lesson: Fix link text
• The Because section summarizes the reason for this PR
• The This PR section has a bullet point list describing the changes in this PR
• If this PR addresses an open issue, it is linked in the Issue section
• If any lesson files are included in this PR, they have been previewed with the Markdown preview tool to ensure it is formatted correctly
• If any lesson files are included in this PR, they follow the Layout Style Guide

[MaoShizhong]

Mainly wording/formatting suggestions. It's a big lesson and I've not quite got the time to dive deeper into the rest of it, but will aim to do so at a later point.

[fcasibu]

Thanks @MaoShizhong I appreciate it!

[MaoShizhong]

Again, mainly nits and suggestions.

Content-wise, fabulous lesson 🤌

Some general things that likely should be changed throughout the file:

• End list items with a period to match most other lessons.
• Capitalise Express, as opposed to express.
• Change "middleware"/"middlewares" to "middleware function" and "middleware functions" respectively, to follow the terminology used by Express itself. The few times Express use "middleware" without "function(s)" after it, it's referring to the general concept of middleware. For example, "application-level middleware" (referring the the middleware functions that are application-level as a whole" or "types of middleware", again being a more "conceptual" use of the word. Whenever it refers to actual functions, it uses "middleware function".

[fcasibu]

Resolved all unresolved comments, let me know if there was a mistake. Thanks

[01zulfi]

@fcasibu this is a chonky lesson 🔥

Particularly love the error handling section. Super cool that it goes through custom errors as well.

Just left a couple of comments below, allow me more time later to dig into the content and code examples.

[01zulfi]

some final comments below

[01zulfi]

lgtm 🚀🚀 🚀