add Rangi (lag)

I tried to set first fallback to Swahili (sw) but failed to do so (I'm not very tech-savvy).

User:Nikerabbit, User:Liuxinyu970226, User:Nemo, is fallback even relevant at such an early point? Isn't it added later, when MessagesLag.php is created?

In any case, I created the patches:

• https://github.com/wikimedia/jquery.uls/pull/255
• https://gerrit.wikimedia.org/r/#/c/351672/

We usually add the fallback already in translatewiki.net, so that users have a good level of service here too and we're ready to go when the translation level is reached.

Oh, got it.

Patches:

• https://gerrit.wikimedia.org/r/#/c/351717/
• https://gerrit.wikimedia.org/r/#/c/351721/

And Swahili looks ok as a fallback.