Add to the Drupal.org: Docker Development Environments Page

[rickmanelius]

Hello! This looks neat for someone looking to get started. I happen to work on the DDEV project, but there are many different use cases and it's great to have different tools for each. To increase visibility, you may want to add this to the following docs page, which contains a growing list of Docker based local dev solutions for Drupal. You could also just link to that from the README.md page instead of having to keep that up to date. Cheers!