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-othersite.yaml

@@ -0,0 +1,20 @@
+port: 17880
+bind_addresses:
+  - "0.0.0.0"
+rtc:
+  tcp_port: 17881
+  port_range_start: 50300
+  port_range_end: 50400
+  use_external_ip: false
+turn:
+  enabled: false
+  domain: localhost
+  cert_file: ""
+  key_file: ""
+  tls_port: 5349
+  udp_port: 443
+  external_tls: true
+keys:
+  devkey: secret
+room:
+  auto_create: false