Fix ID.

docs/_includes/options/setting-default-options.html

@@ -1,5 +1,5 @@
 <section>
-  <h1 id id="setting-default-options">Setting default options</h1>
+  <h1 id="setting-default-options">Setting default options</h1>
 
   <p>
     In some cases, you need to set the default options for all instances of