add "font-feature-settings" css option

[GhostShadow0316]

My vscode and monkeytype both using the "Fira Code" font

this is how my monkeytype text looks

and this is how my vscode looks

I like the way my vscode shows "a" and "g" (see language)

the way I done it is to insert font-feature-settings: '"cv01", "cv02"' in the setting.json file

I wish I can also do this in monkeytype and don't need to try other fonts

[Miodec]

Sorry, I don't think it will be used by enough people to add this. I would recommend using a custom css extension instead.