update proton-ge and improve install to steam

overlays/proton-ge.nix

@@ -5,11 +5,16 @@
 inputs: _final: prev: {
   proton-ge-custom = prev.stdenv.mkDerivation (finalAttrs: rec {
     name = "proton-ge-custom";
-    version = "0.1"; # Made up
+    version = prev.lib.removeSuffix "\n" (builtins.head
+      (builtins.match ".*GE-Proton(.*)"
+        (builtins.readFile "${inputs.proton-ge}/version")));
     src = inputs.proton-ge;
+    # Took from https://github.com/AtaraxiaSjel/nur/blob/cf83b14b102985a587a498ba2c56f9f2bd9b9eb6/pkgs/proton-ge/default.nix
     installPhase = ''
+      runHook preBuild
       mkdir -p $out/bin
       cp -r ${src}/* -t $out/bin/
+      runHook postBuild
     '';
   });
 }