And use a link to local documentation, rather than an
external website in English.
Removed mentions of "in English" for the languages that mentioned it.
https://bugzilla.gnome.org/show_bug.cgi?id=643118
The English originals for these strings in shared-mime-info are
supposed to stay lowercase for some reason, so duplicate them here
and add an English translation that fixes the capitalization.
https://bugzilla.gnome.org/show_bug.cgi?id=640013