The script that preprocess keys and tags metadata from the wiki
was filtering redirect pages when looking for wiki pages with the
template `KeyDescription`.
Some wiki pages like `Key:admin_level` currently redirects to others
like `Tag:boundary=administrative`, but even so, they still contain
a `KeyDescription` template so their metadata can be read by other
programs.
The parameter `eifilterredir` was changed and tested. For more
details, see this parameter in the feature `list=embeddedin` from
https://www.mediawiki.org/w/api.php.