BMI calculator example (#130)

bmi_calculator/lib/main.dart

@@ -0,0 +1,26 @@
+import 'package:bmi_calculator/calculator/calculator_page.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+
+void main() {
+  WidgetsFlutterBinding.ensureInitialized();
+
+  // Prevent landscape orientation
+  SystemChrome.setPreferredOrientations([
+    DeviceOrientation.portraitUp,
+  ]);
+  runApp(const MyApp());
+}
+
+class MyApp extends StatelessWidget {
+  const MyApp({Key? key}) : super(key: key);
+
+  // This widget is the root of your application.
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      title: 'BMI Calculator',
+      home: CalculatorPage(title: 'BMI CALCULATOR'),
+    );
+  }
+}