Adding Extension:Babel configuration for simplewiktionary

This change adds Babel category configurations for the Simple
English Wiktionary. Babel categories has always been in use even
during the times of Template:Babel. This change hence ensures that
the categories are being automatically created, and since such
categories have already existed before, there isn't a need for
community consensus.

Change-Id: I46a55e83e8e823b81726131650a3a2661401bcdf