Allow disabling the emoji picker

I mostly write in French. In this language, you should put a space before double punctuation marks, including colons.
(This should actually be a narrow non-breaking space (U+202F), but most people simply use a plain space which is much easier to type.)

It means that each and every time you type a colon in french, the emoji picker shows up.

This causes a problem when hitting return after a colon, e.g. when starting a list:

> Exemple :
> - Bonjour

You have to press Escape key to be able to press Enter and keep writing. If you don't, a 👍 emoji will appear each time. This is quite annoying!

> Exemple 👍
> - Bonjour