[ENH] Neovim plugin: make path to vectorcode executable configurable

[gpayer]

At the moment the command to be called from the plugin is hardcoded to vectorcode, however in some circumstances it is advantageous to be able so set this manually:

require("vectorcode").setup({
  cmd = vim.fn.expand("~/bin/special-vectorcode-build")
})

E.g. I'm using nixvim and this way I could create a nixvim module which not only includes the plugin but implicitly requires the VectorCode package by using the package relative path to the vectorcode binary.

[Davidyz]

This is WIP in #144. It'll take a while because:

1. I've never used Nix before, but I'm learning some basics so that I can better support this in the future.
2. I made a very bad decision when this project started, and the executable is hardcoded in a lot of different places. feat(cli,nvim): add nix flake and option to specify cli_cmds in nvim #144 mostly covered this, but I need some more time to review it because of the number of changes it involves.

[gpayer]

Hey, that's good to hear! I'll subscribe to the pull request to be up to date on its progress.

If you have any questions regarding nix or need a beta tester, just shoot me a message.

[willruggiano]

@gpayer use PATH? So long as you rename ~/.bin/special-vectorcode-build to ~/.bin/vectorcode and then export PATH="$HOME/.bin:$PATH" in your bashrc, .envrc, whatever.

Or even PATH="$HOME/.bin:$PATH" nvim will work as a one off.

$ vectorcode
fish: Unknown command: vectorcode

$ PATH="./result/bin:$PATH" vectorcode
usage: vectorcode [-h] [--project_root PROJECT_ROOT] [--pipe] [--no_stderr] [-s {bash,zsh,tcsh}] {ls,vectorise,query,drop,hooks,init,version,check,update,clean,prompts,chunks} ...

VectorCode 0.5.6: A CLI RAG utility.