DevX: Add another Matrix site to docker-compose (#3511)

* remove redis, since we dont use it

* update localhost TLS certificat to add *.othersite.m.localhost wildcard

* allow for federation

* Add services and config files for Matrix site othersite.m.localhost

* add element web instance app.othersite.m.localhost

* update README

* exclude synapse database for othersite.m.localhost

* linting

backend/dev_livekit.yaml

@@ -6,11 +6,6 @@ rtc:
   port_range_start: 50100
   port_range_end: 50200
   use_external_ip: false
-#redis:
-#    address: redis:6379
-#    username: ""
-#    password: ""
-#    db: 0
 turn:
   enabled: false
   domain: localhost