Thanks to a tutorial from @swentel my attention got back to webmentions again and I gave the first release candidate for Drupal another try. What's still confusing to me that I have to enter a link-class and a publishing target manually. The former might be a task for a link widget and the latter may be some lack of understanding the API so far.
Updated in January 2020 with significant improvements since originally posted.
Starting a new Drupal 8 project with the LakeDrops composer template only takes less than 3 minutes. And in that short period of time you're note only getting the code base but also a number of extra benefits:
We are so glad to announce that Matthias Walti decided to join LakeDrops. He brings skills and experience in building e-commerce solutions, is a user experience expert and is well known for writing great content which is driven by his marketing background.
Today's new release of Drupal Remote Dashboard (DRD) introduces a big new feature which allows anyone to manage Drupal site updates in a protected and automated framework without having to get any third party involved in the process. Just in time for Independence Day, July 4th 2017. For Drupal site owners this brings independence from external service providers without compromising quality of service or reaction time.