Document how to use Copilot API

[krzwiatrzyk-lgd]

Is your feature request related to a problem? Please describe.
Partially. I want to use Github Copilot as AI API however, there is no documentation regarding how to set it up.

I get following error indicating that authentication is needed however I have no clue how to generate/set those files:

❯ mods Hello

   ERROR  Copilot authentication failed

  failed to get refresh token: no token found in /Users/<user>/.config/github-copilot/hosts.json, /Users/<user>/.config/github-copilot/apps.json

Describe the solution you'd like
Describe in documentation what steps should be performed to make Copilot integration work.

Describe alternatives you've considered
Link to any Github Copilot documentation explaining how to set those files - however I didn't find any.

Additional context
Related PR - #406

[nathabonfim59]

Hi! I'm the author of the PR you referenced

Current situation

As mentioned there, the only official way to generate this file is through their LSP, but it's an obfuscated build and I don't know if it would be a good fit to include an entire LSP into this project.

I've been working on a way to integrate copilot into LazyGit, and have the exact same constraints (built a simple POC there).

I'll file a PR later this weekend. Will mention you guys to test it out.

---

But I want to use mods with Copilot RN!!!

No worries, here is the gist:

• This is not really stated in the GitHub docs because it's an "unofficial" way to use copilot. Originally, it was designed to work with the official VIM LSP, but thanks to the awesome work of talented devs who reverse engineered their APIs, we can use it elsewhere.

• If you want the copilot integration right now, you should install of the apps that already supports it and enable copilot. Either of those will create the necessary files for you:

  1. Zed Editor: https://github.com/zed-industries/zed
  2. Lapce Editor with copilot plugin: https://github.com/lapce/lapce, https://github.com/MinusGix/lapce-copilot
  3. Vim/Neovim: copilot.vim or copilot.lua
  4. Sublime text with copilot plugin: https://github.com/TerminalFi/LSP-copilot

I'm deep into the weeds of this because I'm building an integration to copilot into my own editor

[krzwiatrzyk-lgd]

Thanks a lot for the update! I could make it work using Zed (it took me about 2 minutes). I guess native integration in mods would be better, but that is not so bad.

For all other seeking information, here before any official built-in login:

1. Install Zed code editor.
2. In the right bottom corner, click Copilot icon and select Sign in
3. Proceed with logging in to the browser.