Editorial: change "has" to "have"

ibz096 · annevk · commit 76a371d6dd06 · 2017-11-09T09:53:34.000+01:00
Fixes whatwg#3206.
diff --git a/source b/source
@@ -66005,7 +66005,7 @@ console.log(plasticButton2.getAttribute("is")); // will output "plastic-button"<
 
   <p><span data-x="custom-element-upgrades">Upgrades</span> enable scenarios where it may be
   preferable for <span data-x="custom element definition">custom element definitions</span> to be
-  registered after relevant elements has been initially created, such as by the parser. They allow
+  registered after relevant elements have been initially created, such as by the parser. They allow
   progressive enhancement of the content in the custom element. For example, in the following HTML
   document the element definition for <code data-x="">img-viewer</code> is loaded
   asynchronously:</p>
@@ -120549,6 +120549,7 @@ INSERT INTERFACES HERE
   Ian Davis,
   Ian Fette,
   Ian Kilpatrick,
+  Ibrahim Ahmed,
   Ido Green,
   Ignacio Javier,
   Igor Oliveira,
