add some details

README.md

@@ -19,8 +19,21 @@ Default DB is SQLite.
 
 3. (optional) Set db in config: `nano ${BASEDIR:-.}/files/synapse/homeserver.yaml`
 4. Edit element config: `nano files/element-config.json`
-   1. set "default_server_name" to your domain for Synapse (maybe removed in new version ?)
+   1. set "default_server_name" to your domain for Synapse 
+    - must be manually add in first indention from json, was removed from newer versions (?)
+```json
+{
+    "default_server_name": "ao-it.net",
+    "default_server_config": {
+        "m.homeserver": {
+            "base_url": "https://ao-it.net",
+            "server_name": "matrix.org"
+        },
+...
+```
+    - is need for correct display by registration (else it will display "matrix.org" even if the correct server is addressed in the backend)
    2. set "m.homeserver" => "base_url" to your domain for Element ($DOMAIN variable)
+    - the backend server for synapse
    3. Hint: by default connection to main servers of matrix.org is enabled
    4. Hint: by default jitsi (cloud!) is uses for **group** videocalls 
       - > [^jitsi]: 1:1 calls, or calls between you and one other person, do not use Jitsi. Instead, those calls work directly between clients or via TURN servers configured on the respective homeservers.