Add CMS setup, update frontend pages and layouts, and modify json configs

package.json

@@ -9,12 +9,19 @@
     "lint": "next lint"
   },
   "dependencies": {
+    "@payloadcms/db-mongodb": "^3.54.0",
+    "@payloadcms/next": "^3.54.0",
+    "@payloadcms/payload-cloud": "^3.54.0",
+    "@payloadcms/richtext-lexical": "^3.54.0",
     "bootstrap": "^5.3.3",
-    "next": "14.1.4",
-    "react": "^18",
+    "graphql": "^16.11.0",
+    "next": "15.5.2",
+    "payload": "^3.54.0",
+    "react": "^18.3.1",
     "react-countup": "^6.5.2",
-    "react-dom": "^18",
+    "react-dom": "^18.3.1",
     "react-icons": "^5.5.0",
+    "react-intersection-observer": "^9.16.0",
     "react-modal-video": "^2.0.1",
     "react-scroll-trigger": "^0.6.14",
     "react-skillbars": "^2.2.0",