Add basic Steam Deck instructions

en/getting_started/download_and_install.md

@@ -85,6 +85,26 @@ To install *QGroundControl*:
 * [Android 32 bit APK](https://qgroundcontrol.s3-us-west-2.amazonaws.com/latest/QGroundControl32.apk)
 * [Android 64 bit APK](https://qgroundcontrol.s3-us-west-2.amazonaws.com/latest/QGroundControl64.apk)
 
+## Steam Deck Linux {#steamdeck}
+
+*QGroundControl* can run on the Steam Deck running SteamOS.
+
+Before running *QGroundControl* for the first time:
+1. On the command prompt enter:
+   ```sh
+   sudo usermod -a -G uucp $USER
+   ```
+   <!-- Note, remove install of libqt5gui5 https://github.com/mavlink/qgroundcontrol/issues/10176 fixed -->
+1. Reboot to enable the change to user permissions.
+
+&nbsp;
+To install *QGroundControl*:
+1. Download [QGroundControl.AppImage](https://d176tv9ibo4jno.cloudfront.net/latest/QGroundControl.AppImage).
+1. Upon first run, you will be prompted to allow executing as a program. Select "Allow" and "Never ask again".
+1. For the gamepad to work, the controller action must be set to "Gamepad" and not "Desktop". This can be done by holding the three horizontal line button above the right stick.
+1. To exit the app, switch back to "Desktop" mode and press the L5 button on the back left of the controller.
+1. To ensure the screen doesn't turn off during use, select the battery icon in the tray and select "Manually block sleep and screen locking".
+
 ## Old Stable Releases
 
 Old stable releases can be found on <a href="https://github.com/mavlink/qgroundcontrol/releases/" target="_blank">GitHub</a>.