Add responsive demo page

public/demo/menu/menu.json

@@ -33,6 +33,10 @@
                 {
                     "name": "Accessibility",
                     "to": "/accessibility"
+                },
+                {
+                    "name": "Responsive Design",
+                    "to": "/responsive"
                 }
             ]
         },

src/router/index.js

@@ -537,6 +537,11 @@ const routes = [
         name: 'rating',
         component: () => import('../views/rating/RatingDemo.vue')
     },
+    {
+        path: '/responsive',
+        name: 'responsive',
+        component: () => import('../views/responsive/ResponsiveDemo.vue')
+    },
     {
         path: '/ripple',
         name: 'ripple',