• hides extensions (Option to hide file extensions #3066) on linux and windows, issue can stay open for apple.
• also this PR moves us from the material icon set to nerd-fonts.
• nerd fonts can be thought of as a superset, and in most places I kept using the -md- variants of icons, however, instead of using the outlined variety from md it uses the filled in ones which I think are much more legible
• the nerdfonts cheat sheet is also a bit more useful, because you can reverse-lookup symbols easily, allowing us to use the comments location for a preview (for the people who use nerdfonts in their terminal, which is at-least @tvanderstad & I).

Before:

After:

I also changed the icon for markdown to the hip-and trendy one. I changed the one that svg's use to be the same icon used for the brush within the canvas experience, as well as one that I think creates significantly greater visual separation.