Support commit characters

[MikaelElkiaer]

Feature Description

This is either a feature suggestion, or an inquiry on how to do this.

I was hoping for a straight-forward way to use "trigger" keys to accept selections.
Similar to what VSCode has enabled by default - though it is called "commit characters", see https://code.visualstudio.com/docs/editor/intellisense#_customizing-intellisense.

Looking at the docs and code, I was unable to find anything already implemented.
However, it seems that the "trigger" keys are something could be used as "commit" characters.

If it does not make sense to add a new default, I would like to be pointed in the right direction on how to implement this.

[Saghen]

Waiting for neovim 0.11 to release so we can switch to using vim.on_key (#487) which makes this significantly easier to implement