Merge branch 'wivrn-nixos-lh-env' into 'main'

fossvr/wivrn: Add env vars for NixOS lighthouse setup

See merge request lvra/lvra.gitlab.io!85

content/docs/fossvr/wivrn/_index.md

@@ -123,7 +123,7 @@ Set WiVRn Profile as such:
 Perform a **Clean Build** after changing the CMake flags!
 
 ### NixOS
-Override the `wivrn` package:
+Override the `wivrn` package and launch wivrn-server with the required environment variables:
 ```nix
 {
   services.wivrn = {
@@ -134,6 +134,10 @@ Override the `wivrn` package:
         (lib.cmakeBool "WIVRN_FEATURE_STEAMVR_LIGHTHOUSE" true)
       ];
     });
+    monadoEnvironment = {
+      WIVRN_USE_STEAMVR_LH = "1";
+      LH_DISCOVER_WAIT_MS = "6000";
+    };
   };
 }
 ```