added gamescreen UI and simple start menu

Packages/manifest.json

@@ -8,6 +8,7 @@
     "com.unity.ide.visualstudio": "2.0.25",
     "com.unity.inputsystem": "1.16.0",
     "com.unity.multiplayer.center": "1.0.1",
+    "com.unity.postprocessing": "3.5.1",
     "com.unity.render-pipelines.universal": "17.3.0",
     "com.unity.test-framework": "1.6.0",
     "com.unity.timeline": "1.8.9",

Packages/packages-lock.json

@@ -121,6 +121,15 @@
       "dependencies": {},
       "url": "https://packages.unity.com"
     },
+    "com.unity.postprocessing": {
+      "version": "3.5.1",
+      "depth": 0,
+      "source": "registry",
+      "dependencies": {
+        "com.unity.modules.physics": "1.0.0"
+      },
+      "url": "https://packages.unity.com"
+    },
     "com.unity.render-pipelines.core": {
       "version": "17.3.0",
       "depth": 1,