Include kefír collection by default

[Harvie]

I know it's mentioned in readme. But i think it's so interresting work it should come bundled to icestudio by default: https://github.com/set-soft/collection-kefir_i

But english translation of the whole collection might be bit time consuming :-/

[juanmard]

Why is a comment deleted without reason?

[cavearr]

We are working on block and collection manager, we put your collection in nexts versions of icestudio.

Thanks for your work!