Add aliases for NS 100, 106 on bnwikisource

This patch adds namespace aliases for namespaces
100 (Author) and 106 (Portal) and their respective
talk namespaces per request.

There is no community consensus, but the lack of
these aliases seems merely an ommission; we should
have done that when those localized namespaces
were first set up.

Bug: 59901
Change-Id: I19c829beebd7d802b75c45a0c7f41e7abf4a63e6