[PATCH] Documentation: Merge and update french translations

[Dirk Hohndel]

I applied this patch but the resulting mobile manual is still almost
completely in English. Did something go wrong? Did you want me to push
this as is?

Not quite sure what is the best thing for me to do and I don't want to
break your process as I of course would love to also have a French version
of the Subsurface-mobile user manual available.

Thanks!

/D