Prune community starters list from non-2.x compatible ones #13510
Description
Our README file in spring-boot-project/spring-boot-starters lists Spring Boot starters maintained by the community.
I think we should take the 2.x generation as an opportunity to remove from that lists starters that are no longer maintained or not compatible with Spring Boot 2.x. We should first discuss what should be the requirements for starters to stay on that list.