Add option to convert text and not just word

[ghost]

It would be great to be able to convert a whole text at once

[Rudloff]

We used to have this (see 9e86eeec8d11ec618eaac335d741dc4fa225183d) but it was removed because :

• it made the code much more complicated
• it is way too much work to create an algorithm that correctly detects what words need to be converted (we had a lot of false positives in sentences like « il fait beau »)

That said, it could be implemented as another project that would use Epikoinos as a library but I'm not willing to spend a lot of time on it.

[ghost]

If you advertise beforehand that it might create false positive it can be ok I think. You could just check every word and change the background color in the result for the changed word to allow the user to easily check if the changed word are correct.

[Rudloff]

I created a feature/convert-text branch where I restored this functionality. It mostly works but is experimental and I won't try to improve it on my own.