Simplifies the git_ family of functions to make fish_right_prompt more
readable. git_prompt function is added, which prints the relevant git
prompt information. The git_ family of functions is moved into the
git_prompt function, and fish_right_prompt calls git_prompt
Going forward I'm trying to have modules in charge of the data for
other modules, so I moved the nnn alias call from fish to n, and added a
handy "extraFunctions" config option to fish. Maintaining the fish
module's control of the functions, but allowing others to add stuff in
Refactors the neovim config to use nix modules, and changes the plugins
to favor the builtin neovim LSP over COC. Changes all code to use lua
code instead of vimscript.
