fix: code example syntax highlighting error

Author: bencodezen

src/guide/component-props.md

@@ -324,7 +324,7 @@ app.component('custom-layout', {
   template: `
     <header>...</header>
     <main v-bind="$attrs">...</main>
-    <footer...></footer>
+    <footer>...</footer>
   `
 })
 ```