Onefetch integration

[spenserblack]

Starting this discussion from o2sh/onefetch#1063 (comment), so the entire discussion doesn't end up in one comment chain 😆

Differences from tokei

Significant differences from tokei that need to be handled to switch from tokei to gengo:

• Languages are strings, not enums
• Shell-like languages are collapsed into Shell
• Gengo provides language category, so these can be dropped from onefetch's languages file
• Gengo also provides if the file is detectable, i.e. if it should be reported, so Onefetch can probably drop the -T CLI option
• There is an additional category, Query
• JSX and TSX are just JavaScript and TypeScript
• gengo works on bare repositories, so onefetch could potentially drop the "run on a non-bare repository" error
• Ignores submodules (happy accident)

[spenserblack]

@o2sh Just an FYI that right now I'm collapsing bash, fish, and any other shell or shell-like language into Shell. The reason is that I anticipate a lot of .sh collisions, and shell languages have very similar syntax. I doubt heuristics can reliably disambiguate them.

# my-script.sh
# is this Bash, Dash, or Fish?
echo "Hello, World!"

[spenserblack]

#34