docs(example): make HTML tags into the correct format (#6163)

那里好脏不可以 · web-flow · commit efd234e9032a · 2022-05-24T08:29:49.000+05:30
diff --git a/examples/module-federation/app1/public/index.html b/examples/module-federation/app1/public/index.html
@@ -5,6 +5,6 @@
         <title>App 1</title>
     </head>
     <body>
-        <div id="root"/>
+        <div id="root"></div>
     </body>
 </html>
diff --git a/examples/module-federation/app2/public/index.html b/examples/module-federation/app2/public/index.html
@@ -5,6 +5,6 @@
         <title>App 2</title>
     </head>
     <body>
-        <div id="root"/>
+        <div id="root"></div>
     </body>
 </html>
