Tool to generate a quine commit, and corresponding achievement

[Notgnoshi]

I already took a stab at this: https://github.com/Notgnoshi/herostratus/tree/save/quine but I think there's possibly a better way. I want to revisit.

[Notgnoshi]

I think trying to pick a full SHA-1 hash isn't feasible. 8-character match takes ~30s to search the full range of hashes, and 10-character takes ~1h.

I'm going to defer creating the achievement until after the #120 refactor.