Update homepage, add demos data.

* display ydemo sections dynamically.
* Introduced a new `demos.ts` file for demo content management.
* Added `framer-motion` for animations and updated dependencies in `package.json`.

main-website/package.json

@@ -9,19 +9,20 @@
     "lint": "next lint"
   },
   "dependencies": {
+    "framer-motion": "^12.16.0",
+    "next": "15.3.3",
     "react": "^19.0.0",
-    "react-dom": "^19.0.0",
-    "next": "15.3.3"
+    "react-dom": "^19.0.0"
   },
   "devDependencies": {
-    "typescript": "^5",
+    "@eslint/eslintrc": "^3",
+    "@tailwindcss/postcss": "^4",
     "@types/node": "^20",
     "@types/react": "^19",
     "@types/react-dom": "^19",
-    "@tailwindcss/postcss": "^4",
-    "tailwindcss": "^4",
     "eslint": "^9",
     "eslint-config-next": "15.3.3",
-    "@eslint/eslintrc": "^3"
+    "tailwindcss": "^4",
+    "typescript": "^5"
   }
 }