Text Formatting Shortcuts for YouTube Comments от Remi

This extension creates button shortcuts for quickly applying markdown formatting to YouTube comments as you're writing them.

Features:
- Bold, italic, s̶t̶r̶i̶k̶e̶t̶h̶r̶o̶u̶g̶h̶, and ˢᵘᵖᵉʳˢᶜʳⁱᵖᵗ (may not be supported on all fonts)
- A live preview of what your comment will look like
- Dark mode support

Source code: https://github.com/Germaphobe/yt-comments-extension