Add “name” arg for more-concise CSS

[arrowtype]

From a Twitter thread:

@arrowtype: Could the tool allow an abbreviation of the family name? “Recursive Sans Linear Light” is pretty long. 😅

I think the full name picks up local fonts, right? Even if this is the goal, it might make sense to abbreviate the class names. I suppose a user could find/replace, though.

@PixelAmbacht: For the class/variable name, maybe passing a "CSS name" would be cool. Like -n "boink" to get --boink-liga.

That seems useful!

Also, potentially, the @font-face could have font-family: "boink";. But, alternatively, the CSS could give users a shortened CSS variable to use for the long font name, like var(--boink).

I do recognize that there may be edge cases wherein a user might want to pass in two fonts, and perhaps the short names could clash. This would probably have to help users avoid that, if it is possible.