proton: Load environment overrides from a file on disk

user_settings.sample.py

@@ -0,0 +1,22 @@
+#!/usr/bin/python2.7
+
+#to enable these settings, name this file "user_settings.py"
+
+user_settings = {
+    #logs are saved to $HOME/steam-$STEAM_APP_ID.log, overwriting any previous log with that name
+    "WINEDEBUG": "+timestamp,+pid,+tid,+seh,+debugstr",
+
+    "DXVK_LOG_LEVEL": "info",
+
+    #Enable DXVK's HUD
+#    "DXVK_HUD": "devinfo,fps",
+
+    #Use wined3d for d3d11 instead of dxvk
+#    "PROTON_USE_WINED3D11": "1",
+
+    #Disable d3d11 entirely
+#    "PROTON_NO_D3D11": "1",
+
+    #Disable in-process synchronization primitives
+#    "PROTON_NO_ESYNC": "1",
+}