doc: Add section about using jitsi-meet-electron-utils from source

README.md

@@ -11,6 +11,25 @@ from config.js
 npm install
 ```
 
+## Working with the [jitsi-meet-electron-utils](https://github.com/jitsi/jitsi-meet-electron-utils) sources
+By default the jitsi-meet-electron-utils is build from its git repository sources. The default dependency path in package.json is :
+```json
+"jitsi-meet-electron-utils": "jitsi/jitsi-meet-electron-utils"
+```
+
+To work with local copy you must change the path to:
+```json
+"jitsi-meet-electron-utils": "file:///Users/name/jitsi-meet-electron-utils-copy",
+```
+
+To make the project you must force it to take the sources as `npm update` will not do it.
+```bash
+npm install jitsi-meet-electron-utils --force
+node_modules/.bin/electron-rebuild
+```
+
+NOTE: Also check jitsi-meet-electron-utils's [README](https://github.com/jitsi/jitsi-meet-electron-utils/blob/master/README.md) to see how to configure your environment.
+
 ## Statring the application
 ```bash
 npm start