added type doc to menu related files

src/app/shared/menu/menu-item/text-menu-item.component.ts

@@ -0,0 +1,19 @@
+import { Component, Inject, Input } from '@angular/core';
+import { TextMenuItemModel } from './models/text.model';
+import { MenuItemType } from '../initial-menus-state';
+import { rendersMenuItemForType } from '../menu-item.decorator';
+
+/**
+ * Component that renders a menu section of type TEXT
+ */
+@Component({
+  selector: 'ds-text-menu-item',
+  templateUrl: './text-menu-item.component.html',
+})
+@rendersMenuItemForType(MenuItemType.TEXT)
+export class TextMenuItemComponent {
+  @Input() item: TextMenuItemModel;
+  constructor(@Inject('itemModelProvider') item) {
+    this.item = item;
+  }
+}