Update README.md (using the Drupal template) and module page for 10.x

Should be adjusted finally right before the 11.0 release!

Here are a few updates that I would say are appropriate for the recent changes. Apart from that, the README is still pretty up-to-date for 11.x.

@lrwebks I think a link for adding ad contents would be helpful as last step to use the module?

Added that, as well as some other things that I remembered, that should probably be in the README.

Perfect