[Feature Request]: TOC generation for Markdown editor

[TheRealBeef]

Feature Description

Since we cannot switch editors, and for some code-heavy content its much easier to write it in Markdown, it would be nice if the autogenerated TOC functionality from the Block Editor (I'm not sure if its present in the WYSIWYG editor) would work in the markdown editor.

I couldn't find anything in documentation or a search into the history here, so my assumption is that this is a feature request.

I am on Publii 0.46.3.