Add editor option in menu

[zabidenhtf]

It can be so helpful. And it good idea

[petitlapin]

yes, this one would be nice, I just had to browse the code to understand how to unlock it so for sure it's not a good way!

One pain part of it would be to add a visual button (because of how they are handled in the Li-Ri-devel repo) and we would need to keep the same graphical style too.

Edit: I just started to play a bit with it and we will need to also improve its usability. For now, we have no easy way (except browsing the source code) to know which button does what.
And another issue with existing code is that if we add text, it needs to be images (for all languages...)