Please update README.md

[mcm1957]

The main README.md at repository root sould be written in pure english- Of course ist ok to add a README-de.md (or Readmes for other languages. Und ist ok too to add a link insode the main README.md

If you want to prodvide documentation for users those files should be located at doc directory.

And please a omplete changelog to README.md. Users should be able to resd what has changes between current statble and current (latest) release