Issue:#6 Add reusable bottom navigation widget

lib/widgets/bottomNav_chithra.dart

@@ -0,0 +1,91 @@
+import 'package:flutter/material.dart';
+
+class BottomNavChithra extends StatefulWidget {
+  const BottomNavChithra({Key? key}) : super(key: key);
+
+  @override
+  State<BottomNavChithra> createState() => _BottomNavChithraState();
+}
+
+class _BottomNavChithraState extends State<BottomNavChithra> {
+  int _currentIndex = 0;
+
+  final List<Widget> _screens = [
+    const HomeScreen(),
+    const MenuScreen(),
+    const ProfileScreen(),
+  ];
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: _screens[_currentIndex],
+      bottomNavigationBar: BottomNavigationBar(
+        currentIndex: _currentIndex,
+        onTap: (index) {
+          setState(() {
+            _currentIndex = index;
+          });
+        },
+        items: const [
+          BottomNavigationBarItem(
+            icon: Icon(Icons.home),
+            label: 'Home',
+          ),
+          BottomNavigationBarItem(
+            icon: Icon(Icons.restaurant_menu),
+            label: 'Menu',
+          ),
+          BottomNavigationBarItem(
+            icon: Icon(Icons.person),
+            label: 'Profile',
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+/* -------- Placeholder Screens -------- */
+
+class HomeScreen extends StatelessWidget {
+  const HomeScreen({Key? key}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return const Center(
+      child: Text(
+        'Home Screen',
+        style: TextStyle(fontSize: 22),
+      ),
+    );
+  }
+}
+
+class MenuScreen extends StatelessWidget {
+  const MenuScreen({Key? key}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return const Center(
+      child: Text(
+        'Menu Screen',
+        style: TextStyle(fontSize: 22),
+      ),
+    );
+  }
+}
+
+class ProfileScreen extends StatelessWidget {
+  const ProfileScreen({Key? key}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return const Center(
+      child: Text(
+        'Profile Screen',
+        style: TextStyle(fontSize: 22),
+      ),
+    );
+  }
+}