Rated 4 out of 5 stars

Nice. But it seems that footnotes are not supported, or are they? That is, something like https://www.markdownguide.org/extended-syntax#footnotes

Also, a keyboard shortcut to toggle rendered/raw views would be very appreciable.

Otherwise, nice job, thanks.

This review is for a previous version of the add-on (3.1.1). 

Ctrl+Alt+M is the default hotkey. You can change it in the preferences.

Footnotes... not really. You can try this suggestion I copied over from the original Markdown Here: https://gitlab.com/jfx2006/markdown-here-revival/-/wikis/Tips-and-Tricks#footnotes