increase transifex bus factor: add maintainers

[ThomasWaldmann]

@RogerHaase @UlrichB22 do you have a transifex account name or email I could add to grow the bus factor there?

https://app.transifex.com/thomaswaldmann/MoinMoin/dashboard/

[RogerHaase]

I have no account at transifex, I only speak English.

[ThomasWaldmann]

@RogerHaase ok. they point was mainly having > 1 person there with admin capabilities (does not require translating).

@UlrichB22 Maybe you?

[UlrichB22]

Sorry, I don't want to use this service. German translations are done for about 95% of strings.

[sebix]

I can step in here if you want

[ThomasWaldmann]

@sebix I accepted your join request now, sorry for the delay and thanks for helping!

One of the active devs here needs to push updated i18n files now and then to transifex, not sure when that happened last time.