Add workaround for EA App failing to launch to Linux installation ins…

…tructions (#308)

and replace mention specific to Nvidia GPUs that is no longer relevant.

docs/steamdeck-and-linux/installing-on-steamdeck-and-linux.md

@@ -15,11 +15,18 @@ NorthstarProton has some problems and may stop working at any point, if this hap
 On Steam Deck, complete the following in desktop mode. You may return to game mode once completed _(A mouse + keyboard plugged into the Deck are recommended for easier navigation of menus)_
 
 1. Make sure you ran the vanilla version of Titanfall2 at least once on Linux!
-   * If you use an Nvidia GPU you may need to start the game using Proton 6.3-8 for the first time
+   * If Titanfall 2 fails to launch, you may have to delete the game's Proton prefix and reinstall using another version of Proton.
+   1. To do this, head to `~/.local/share/Steam/steamapps/compatdata` if you installed Steam via a native package, or the Flatpak equivalent.
+   2. Delete the folder named `1237970`
+   3. Set Titanfall 2 to launch with `Proton 6.3-8` or `Proton 7.0-6` in the _Properties_ -> _Compatibility_ section.
+   4. Launch the game and allow the install to completely finish.
+   5. Set Titanfall 2 to launch with a more current version of Proton, NorthstarProton, or Proton GE.
+   6. If Titanfall 2 still fails to launch, delete the prefix again and try installing with the other version of Proton.
 2. Install the latest version of Northstar using [FlightCore](../installing-northstar/northstar-installers#geckoeidechse-flightcore), [Viper](../installing-northstar/northstar-installers#0negal-viper), or do it manually
    1. For manual install download the latest version of Northstar from the [releases](https://github.com/R2Northstar/Northstar/releases) page
    2. Then extract all contents of the file to your Titanfall 2 folder ( Right click _Titanfall 2_ > Open _Properties_ > Click _Local Files_ > Click _Browse_ )
-3. Install NorthstarProton
+3. Install NorthstarProton or a current version of Proton GE.
+   * In some user cases, NorthstarProton may not work. You may instead try Proton GE, which is also available through the following methods.
    1. **Protonup-QT**: Click _About_, then tick the box to enable _advanced mode_. You should be able to select and install NorthstarProton from the _Add version_ menu.
    2. **ProtonPlus**: NorthstarProton can also be installed via ProtonPlus.
    3. **Manual**: Download the latest release of [NorthstarProton](https://github.com/cyrv6737/NorthstarProton/releases/), extract it, and place the folder in one of the following directories: