Add aliases for some other non-wikipedia projects

The Kiwix folks requests wikivoyage aliases, and we might as well add some
more projects to the list while we are at it. We are using the list of
Wikipedias for languages, which will certainly result in more language
prefixes than actually exist in the smaller projects. This is harmless though,
as requests for undefined prefixes will result in an error too.

Change-Id: I3e9c03566c43603590f369944db0707131435f66
Merge "Add aliases for some other non-wikipedia projects"