Add a favicon

[faustinoaq]

Hi @jhass !

I think would be nice to have a favicon on https://play.crystal-lang.org/#/cr and https://carc.in/#/cr WDYT?

[jhass]

Sure, make one 😉 I'd prefer something general though, less so something crystal specific.

[faustinoaq]

@jhass Oh, nice! I gonna do it then 👍

[faustinoaq]

Hi @jhass WDYT about this one:

Source: https://gist.github.com/faustinoaq/147a266993ec8388f4f713d47e29bf17

Original author: https://openclipart.org/user-detail/ilnanny by @ilnanny

[jhass]

I guess we could go with a cogwheel, though it feels quite generic tbh.

This particular one I think might be a bit too detailed, especially for a favicon, don't you think? I think in general I would prefer some flat design too.