First draft for matrix server setup

config/element_config.template.json

@@ -0,0 +1,11 @@
+{
+  "default_server_config": {
+    "m.homeserver": {
+      "base_url": "https://matrix.${DOMAIN}",
+      "server_name": "matrix.${DOMAIN}"
+    }
+  },
+  "disable_custom_urls": true,
+  "disable_guests": true,
+  "brand": "My Matrix"
+}