Add section for mod manager integration with Steam/Proton

content/docs/steamvr/mod-managers.md

@@ -0,0 +1,36 @@
+---
+weight: 200
+title: Using Mod Managers
+---
+
+# Using Third-Party Mod Managers with Steam Games
+
+This is a guide on how to install and integrate mod managers (like Vortex, MO2, etc.) for games running in Proton.
+Most of this stuff will break if you use Flatpak for any of the involved programs.
+
+![skyrim_vr_vortex](/images/steam_launch_vortex.png "Example usage Vortex Mod Manager integrated into Skyrim VR on Steam")
+
+1. Setup `Protontricks` & `Steam Metadata Editor`
+2. Install your steam game & **launch it** once
+3. Download your mod manager installer (Vortex, MO2 etc.)
+4. Run the installer with `Protontricks Launcher`, select your game when prompted
+5. Finish the installer, note the install path
+6. Symlink mod manager's installation path inside prefix into the game's install path. For example:
+```
+ln -s "/home/faith/.local/share/Steam/steamapps/compatdata/611670/pfx/drive_c/Program Files/Black Tree Gaming Ltd/Vo
+rtex/" "/home/faith/.local/share/Steam/steamapps/common/SkyrimVR/Vortex"
+```
+7. **Close Steam!** Then open Steam Metadata Editor
+8. Find your game in the list, then click "Edit launch menu"
+9. Click "Add New Entry"
+10. In Description enter the display name (e.g. "Vortex Mod Manager")
+11. Click on the "..." button in Executable field
+12. File picker will appear which should be inside game's install directory. If it's not, try again or restart your computer or perform some ritual because it sometimes doesn't work properly.
+13. Choose the mod manager executable (e.g. Vortex -> Vortex.exe)
+14. Make sure a relative path appears in the Executable field! It won't work otherwise. (e.g. ("Vortex/Vortex.exe"))
+15. Working directory should fill-in automatically
+16. Close the modal window
+17. Click "Save" button
+18. Enjoy
+
+You have to install mod manager for each game seperately.