fix: homogenize markdown across files using markdownlint rules (#6988)

* chore: homogenize C# table of content anchor (`#c-sharp` to `#csharp`)

* format: homogenize c# category title

right markdown escape instead of use HTML entities

* lint: fix `MD012/no-multiple-blanks` rule

Multiple consecutive blank lines [Expected: 2; Actual: 3]

* lint: fix `MD039/no-space-in-links`

Spaces inside link text

* lint: fix `MD009/no-trailing-spaces` rule

Trailing spaces [Expected: 0 or 4; Actual: 1]
Trailing spaces [Expected: 0 or 4; Actual: 2]

* lint: fix `MD006/ul-start-left` rule

* format: remove extra spaces between note tokens

* spell: fix lint `MD044/proper-names` rule

- HTML
- JavaScript
- YouTube

* spell: normalize to the most common `Index` heading

* lint: fix `MD007/ul-indent` rule

Unordered list indentation [Expected: 4; Actual: 2]

* format: escape pipes `|` from resources text

addresses #5176

* add Hesham Asem courses about machine and deep learning and nlp

* Expand the name of nlp section

* Change the order

* Revert "spell: normalize to the most common `Index` heading"

This reverts commit 4d6a74e7d7.

Co-authored-by: AhmedElTabarani <eltabaraniahmed@gmail.com>

courses/free-courses-ko.md

@@ -16,9 +16,9 @@
 * [iOS](#ios)
 * [Java](#java)
 * [JavaScript](#javascript)
-  * [AngularJS](#angularjs)
-  * [Node.js](#node.js)
-  * [React.js](#react.js)
+    * [AngularJS](#angularjs)
+    * [Node.js](#node.js)
+    * [React.js](#react.js)
 * [Kotlin](#kotlin)
 * [Linux](#linux)
 * [Machine Learning](#machine-learning)
@@ -266,7 +266,7 @@
 * [Web2-CSS](https://www.opentutorials.org/course/3086) (생활코딩)
 * [Web2-Domain name system](https://www.opentutorials.org/course/3276) (생활코딩)
 * [Web2-Home server](https://www.opentutorials.org/course/3265) (생활코딩)
-* [Web2-javascript](https://www.opentutorials.org/course/3085) (생활코딩)
+* [Web2-JavaScript](https://www.opentutorials.org/course/3085) (생활코딩)
 * [Web2-nodejs](https://www.opentutorials.org/course/3332) (생활코딩)
 * [Web2-PHP](https://www.opentutorials.org/course/3130) (생활코딩)
 * [Web2-Python](https://www.opentutorials.org/course/3256) (생활코딩)