docs: bring back docs from eo files by switching to the new group name

docs: bring back docs from eo files by switching to the new group name

During the migration of docs to the eo file the group name changed to have a
Elm_ prefix which resulted in our docs not including this group and not showing
any of the docs in there. Switching to the new name fixes this.

Having this prefix makes sense especially as we are now merging elm into efl.

Hopefully that will be the last change.

@fix

Ref T3109