feat(#49): exposing suggestion_group in config settings

[AlejandroSuero]

With this changes suggestion_group will be exposed to the config under config.color like:

require("supermaven-nvim").setup({
  color = {
    suggestion_group = "Comment",
  },
})

Allowing users to change it in an easier way.

---

suggestion_group-changes-demo.mp4

Closes #49.

[AlejandroSuero]

@sm-victorw @super-jacob When discussing the behaviour on #49 about how SupermavenSuggestion highlight group is set. I tested out using lazy.nvim changing it from lazy = false to event = "VeryLazy" and here are the results:

SupermavenSuggestion-not-loading-on-events.mp4

Should I change this behaviour to create the group SupermavenSuggestion when loading the plugin in this PR, or create another PR with those changes?

EDIT:

Apparently @arnevm123 has created one PR solving this in #53.

[AlejandroSuero]

@sm-victorw @super-jacob the changes will be the following:

Delete setting SupermavenSuggestion group in document_listener.lua on VimEnter and left only on ColorSchem event.

And set SupermavenSuggestion group in init.lua in M.setup(args) function without creating an autocmd on events.