Add a more complete and simple example of a syntaxically SyntaxHighlighter

[1641585051]

Godot version: 4.5.1

Issue description: The Dictionary _GetLineSyntaxHighlighting(int line) function of SyntaxHighlighter si completely icomprehensible that causes me to not be able to accurately locate the highlight,and _GetLineSyntaxHighlighting function lacks more practical instructions and examples

URL to the documentation page (if already existing): https://docs.godotengine.org/en/stable/classes/class_syntaxhighlighter.html#class-syntaxhighlighter-method-get-line-syntax-highlighting

[Ayush41]

Yes, The current documentation explains the return format but lacks a complete, practical example of implementing a custom SyntaxHighlighter.
I’ll have to add a minimal working example that shows how to read a line from TextEdit and return highlighting regions. This should make the method much easier to understand.