Update the module page and README.md for 2.x

Problem/Motivation

The module page currently doesn't seem to reflect the 2.x status. Instead it seems to show the Drupal 7 status. That's not good.

Would be great, if someone could provide an up to date README.md describing everything important and use that as basis for the module page then!

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes