feat(completion): add nvim-cmp-buffer-lines

[Axlefublr]

📑 Description

Adds the nvim-cmp-buffer-lines nvim-cmp source, but instead of just adding it to normal completions, keeps it local to a hotkey.

The reasoning for this is that, even with a low priority, whole line completions end up being super annoying, when mixed in with all the other (usually more useful) suggestions. So it's for this reason that this source is effectively "opt-in".

The mapping used is <C-x><C-l>, because that's the default way to do whole line completions. What you basically get with this community pack, is you replace built in whole line completions with ones that use nvim-cmp.

The hotkey is wack, but it is default! So I think it makes the most sense, even if there could be other, more ergonomic mappings.

At the very least, if a person wants the functionality, but on a different mapping, they now have the option to take a peek at this community pack, copy paste it into their config, and change the mapping to what they want.

ℹ Additional Information

[github-actions]

Review Checklist

Does this PR follow the [Contribution Guidelines](development guidelines)? Following is a partial checklist:

Proper conventional commit scoping:

• If you are adding a new plugin, the scope would be the name of the category it is being added into. ex. feat(utility): added noice.nvim plugin

• If you are modifying a pre-existing plugin or pack, the scope would be the name of the plugin folder. ex. fix(noice-nvim): fix LSP handler error

• Pull request title has the appropriate conventional commit type and scope where the scope is the name of the pre-existing directory in the project as described above

• README is properly formatted and uses fenced in links with <url> unless they are inside a [title](url)

• Proper usage of opts table rather than setting things up with the config function.

[Uzaaft]

Curious as to if you want to keep the note about or not. Besides that, this looks good!

[Axlefublr]

You wanted me to remove it, no?

[Uzaaft]

You wanted me to remove it, no?

I moved it to under the repository link 😅

[Uzaaft]

Nice. I was wondering why you weren't in the discord anymore. Seeing this PR from you made my day @Axlefublr