Update index.html (#61448)

src/ProjectTemplates/Web.ProjectTemplates/content/ComponentsWebAssembly-CSharp/wwwroot/index.html

@@ -6,6 +6,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <title>ComponentsWebAssembly-CSharp</title>
     <base href="/" />
+    <link rel="preload" id="webassembly" />
     <!--#if SampleContent -->
     <link rel="stylesheet" href="lib/bootstrap/dist/css/bootstrap.min.css" />
     <!--#endif -->