fix(components-examples): rename example component to follow naming convention for autoloading in docs

Author: annieyw

src/components-examples/material/menu/index.ts

@@ -5,20 +5,20 @@ import {MatMenuModule} from '@angular/material/menu';
 import {MenuIconsExample} from './menu-icons/menu-icons-example';
 import {MenuOverviewExample} from './menu-overview/menu-overview-example';
 import {MenuPositionExample} from './menu-position/menu-position-example';
-import {NestedMenuExample} from './nested-menu/nested-menu-example';
+import {MenuNestedExample} from './menu-nested/menu-nested-example';
 
 export {
   MenuIconsExample,
   MenuOverviewExample,
   MenuPositionExample,
-  NestedMenuExample,
+  MenuNestedExample,
 };
 
 const EXAMPLES = [
-  MenuIconsExample,
-  MenuOverviewExample,
-  MenuPositionExample,
-  NestedMenuExample,
+    MenuIconsExample,
+    MenuOverviewExample,
+    MenuPositionExample,
+    MenuNestedExample,
 ];
 
 @NgModule({

src/components-examples/material/menu/nested-menu/nested-menu-example.css renamed to src/components-examples/material/menu/menu-nested/menu-nested-example.css

@@ -0,0 +1,11 @@
+import {Component} from '@angular/core';
+
+/**
+ * @title Nested menu
+ */
+@Component({
+  selector: 'menu-nested-example',
+  templateUrl: 'menu-nested-example.html',
+  styleUrls: ['menu-nested-example.css'],
+})
+export class MenuNestedExample {}

src/components-examples/material/menu/nested-menu/nested-menu-example.html renamed to src/components-examples/material/menu/menu-nested/menu-nested-example.html

@@ -93,7 +93,7 @@ that should trigger the sub-menu:
 </button>
 ```
 
-<!-- example(nested-menu) -->
+<!-- example(menu-nested) -->
 
 ### Lazy rendering
 By default, the menu content will be initialized even when the panel is closed. To defer