Add <LinkPreload /> to BlazorWeb template

Author: maraf

src/ProjectTemplates/Web.ProjectTemplates/content/BlazorWeb-CSharp/BlazorWeb-CSharp/Components/App.razor

@@ -5,6 +5,7 @@
     <meta charset="utf-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <base href="/" />
+    <LinkPreload />
     @*#if (SampleContent)
     <link rel="stylesheet" href="@Assets["lib/bootstrap/dist/css/bootstrap.min.css"]" />
     ##endif*@