added new prefabs, added scene load manager

Packages/manifest.json

@@ -4,6 +4,7 @@
     "com.unity.animation.rigging": "1.2.1",
     "com.unity.cinemachine": "2.9.5",
     "com.unity.collab-proxy": "2.0.0",
+    "com.unity.formats.fbx": "4.2.1",
     "com.unity.ide.rider": "3.0.18",
     "com.unity.ide.visualstudio": "2.0.17",
     "com.unity.ide.vscode": "1.2.5",

Packages/packages-lock.json

@@ -1,5 +1,12 @@
 {
   "dependencies": {
+    "com.autodesk.fbx": {
+      "version": "4.2.1",
+      "depth": 1,
+      "source": "registry",
+      "dependencies": {},
+      "url": "https://packages.unity.com"
+    },
     "com.unity.ai.navigation": {
       "version": "1.1.1",
       "depth": 0,
@@ -51,6 +58,16 @@
       "dependencies": {},
       "url": "https://packages.unity.com"
     },
+    "com.unity.formats.fbx": {
+      "version": "4.2.1",
+      "depth": 0,
+      "source": "registry",
+      "dependencies": {
+        "com.unity.timeline": "1.7.1",
+        "com.autodesk.fbx": "4.2.1"
+      },
+      "url": "https://packages.unity.com"
+    },
     "com.unity.ide.rider": {
       "version": "3.0.18",
       "depth": 0,