update README

README.md

@@ -7,6 +7,8 @@ A small html/js project to nudge a user to use the desktop client for Jitsi.
 All settings live in `assets/config.json`, loaded at startup. The launcher stays
 up but links break if the file is missing or malformed.
 
+Rename `assets/config.json.sample` to `assets/config.json`.
+
 | Parameter | Description |
 | --- | --- |
 | `jitsiLauncher` | Domain of this Jitsi launcher. Used for the meeting URLs created by the meeting creator (Nextcloud, adhoc link). |