Prepare Feature highlights for 1.4.0

As discussed today with @Sporiff we thought it might be helpful to have some blogposts highlighting features that are either shipped or prepared with the upcoming 1.4.0 release in order to explain better, what we are actually doing and planning to do.

Those are things we already merged:

• Prohibit the creation of new users using django's createsuperuser command in favor of our own CLI entry point. Run funkwhale-manage fw users create --superuser instead. (funkwhale#1288 (closed))
• Add a management command to generate dummy notifications for testing
• Cache radio queryset into redis. New radio track endpoint for api v2 is /api/v2/radios/sessions/{radiosessionid}/tracks (funkwhale#2135 (closed))
• New management command to update Uploads which have been imported using --in-place and are now stored in s3 (funkwhale#2156 (closed))
• Maloja: Submit album artists and duration and allow to disable server side metadata fixing

We do have more things merged which are the basements for new features, if you want me to list them to, let me know.

I am handing this over to our @funkwhale/communications team :)