Add French translation #1
This is completely untested, because why would I do something properly?
I added a bunch of comments with the thoughts I had or decisions I made while translating. It sounded like this file has a lot of strings that should not actually be translatable and should instead remain internal.
Deleting a branch is permanent. Although the deleted branch may exist for a short time before cleaning up, in most cases it CANNOT be undone. Continue?