* Add button to purge rooms to room list
Add button (BulkDeleteButton) to delete rooms with no local users:
- purge rooms `POST /_synapse/admin/v1/purge_room`
(https://github.com/matrix-org/synapse/blob/master/docs/admin_api/purge_room.md)
* Bugfix of merge 'master'
* Change from purge room to delete room endpoint
Add further attributes:
- is_encrypted
- federatable
- public
- state_events
- version
- joined_local_members
Also add the ability to sort.
API was added by synapse v1.13.0.
