[de] Update otp-supervisors.md (#2101)
[de] Update otp-supervisors.md (#2101)

* Update otp-supervisors.md

German translation matches the English version, so I also changed the version at the top of the file.

* Update otp-supervisors.md

I manually merged my previous commit in to this one now.

* Update otp-supervisors.md

fix a little grammatical error

nscyclone/elixir-school,doomspork/elixir_school,doomspork/elixir-school,nscyclone/elixir-school,nscyclone/elixir-school,doomspork/elixir_school,doomspork/elixir-school,doomspork/elixir-school,nscyclone/elixir-school,doomspork/elixir_school