Updated End user guide (markdown)

End-user-guide.md

@@ -20,6 +20,11 @@ This is work in progress and also never finished, as new functionality and also
 ## Setting up Wifi
 * See [Home](https://github.com/Aircoookie/WLED/wiki), step 3, 4 and 5
 
+## Updating WLED
+...
+### Advanced: Saving Configuration files
+E.g. in case of factory reset or esphome install
+* Just go to the [WLED-IP]/edit page and download the cfg.json and presets.json files (right click on file name)! To restore, you just delete the existing ones, upload the ones you downloaded for the backup and reboot (from [Issue 146](https://github.com/Aircoookie/WLED/issues/146))
 ## Troubleshooting
 ### All WLED settings gone
 For instance due to crash, factory reset or update