Material icon medium dartpad demo (#75)

* Material icon medium dartpad demo

* removed unnecessary widget cast

* wrapped with scaffold and center

Author: JoseAlba

medium/material_icons/dartpad_metadata.yaml

@@ -0,0 +1,4 @@
+name: Material Icons Demonstration
+mode: flutter
+files:
+  - name: main.dart

medium/material_icons/main.dart

@@ -0,0 +1,46 @@
+import 'package:flutter/material.dart';
+
+void main() => runApp(MyApp());
+
+class MyApp extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      title: 'Material Icon Demo',
+      home: MyHomePage(),
+    );
+  }
+}
+
+class MyHomePage extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: Center(
+        child: Row(
+          mainAxisAlignment: MainAxisAlignment.spaceAround,
+          children: const [
+            Icon(
+              Icons.masks_rounded,
+              color: Colors.pink,
+              size: 24.0,
+              semanticLabel: 'Wear a mask',
+            ),
+            Icon(
+              Icons.wash_rounded,
+              color: Colors.green,
+              size: 30.0,
+              semanticLabel: 'Wash your hands',
+            ),
+            Icon(
+              Icons.six_ft_apart_rounded,
+              color: Colors.blue,
+              size: 36.0,
+              semanticLabel: 'Socially distance',
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}