Editorial: Fix typo in example in Namespaces section (#593)

sideshowbarker · tobie · commit 5a20e34e8d2a · 2018-12-07T12:45:10.000+01:00
diff --git a/index.bs b/index.bs
@@ -4408,7 +4408,7 @@ Of the extended attributes defined in this specification, only the [{{Exposed}}]
 
 <div class="example" id="example-namespace">
 
-    The following [=IDL fragment=] defines an
+    The following [=IDL fragment=] defines a
     [=namespace=].
 
     <pre highlight="webidl">
