feat: switch nvim-cmp for blink.cmp

[Saghen]

Opening as draft since I have yet to verify everything works as expected

Closes #1331

[cmdrrobin]

Tested and works fine. Although before nvim-cmp, it shows the documentations. Maybe we need to enable for blink.cmp as well.

opts = {
  completion = {
    -- Show documentation when available, with a small delay.
    -- If you're noticing high CPU usage or stuttering when opening the
    -- documentation, you may try setting
    -- `completion.documentation.treesitter_highlighting = false`.
    documentation = {
      auto_show = true,
      auto_show_delay_ms = 200,
    },
  },
}

UPDATE: don't know if it is my system, but couldn't trigger show/hide documents with default keymaps. (<C-Space>)

[raRaRa]

What's the status on this? :)

[oriori1703]

fwiw, I have been using a version of this PR for over a week, and experienced no issues :D

[Saghen]

Although before nvim-cmp, it shows the documentations. Maybe we need to enable for blink.cmp as well.

I've left this off by default but included a section about turning it on. This matches the behavior of built in completions and other major editors (i.e. vscode). I personally prefer the <C-Space> binding to show it as needed.

[feoh]

This looks brilliant.

Not sure how to evaluate this versus the 'default completion' PR.

I know I personally would rather see new users have this experience but I haven't honestly tried the default yet so I'll go test and and report back, and see if we can't get this resolved with a modicum of screaming :)

Thank you!

[feoh]

This is so very slightly slower than the 'native' completions as shown in the PR from @cmdrrobin .

However I personally favor the vastly increased flexibility available with different providers and the like.

Thus far I've seen way more strenuous opinions around a desire for the native completions support so I'm feeling rather like King Solomon at the moment :)

[Saghen]

This is so very slightly slower than the 'native' completions

What the hell, sounds like I have some work for the weekend :) Which LSP?

[feoh]

basedpyright. This is just my perception and I didn't do any formal benchmarking.

I'm not sure HOW I'd benchmark the two actually. I should look into that :)

[cmdrrobin]

@feoh to be honest, I don't think it is worth the benchmark the two actually. ;-)

[feoh]

You know what? I've seen several votes in favor of this PR and we don't have anyone who can support the 'native' version, so with thanks to @cmdrrobin and @Saghen for their hard work and participation I'm merging this.

Great work all!