Add command auto-complete pop up

[occluder]

For a lot of people, going through custom commands in settings to look for something takes time and isn't fun. So I want to propose the addition of an auto-complete popup for commands, similar to emotes starting with :

Here's my idea of how it could look like:

I think this feature will make a lot of people happy, and I don't see why anyone would oppose it.
To my knowledge, it also doesn't sound like a big task considering that the popup and string searching functionality already exist

[x9136]

This is a useful idea because it will make it easier to interact with chat. I would like to add to it.

Many channels have bots with their own set of commands: Moobot, Nightbot and others. These bots usually have an API and a public list of commands.

Thus, it may be possible to pull up commands that are relevant to the channel and offer them for autocompletion.