README could be redesigned to show selected features instead of all

[erik-brangs]

As an end-user (i.e. web application developer), I'm interested in the Jakarta Eclipse Language Server. When the code is ready to try out for end-users (see #120, #137), consider redesigning the README to show case a "best of" for features instead of all the features. The current feature list is already comparatively long and is likely to grow further.

Such a redesign would allow potential users to judge if a potential plugin could be interesting to them. The full feature list can still be linked from the readme.