Fisher compatibility

[chvolkmann]

Apart from this repo, there's also code-connect-fish-plugin which is used for quick installation through

fisher install chvolkmann/code-connect-fish-plugin

I believe fisher supports repos that do not adhere to its expected structure. It's preferable to put the fisher integration into this repo as well, so you can simply run

fisher install chvolkmann/code-connect

instead. Also maintaining two repos is annoying.

Resolves #3

This puts code_connect.py into the functions folder, so fisher can discover it automatically. Along with it, code.fish sets up the alias to code_connect.py