Chore: fix ReSpec errors

Author: Marcos Cáceres

index.html

@@ -165,9 +165,9 @@ <h2>
           server</a>.
         </p>
         <p>
-          A <a>push message</a> is delivered to the <a>active worker</a> associated with the
-          <a>push subscription</a> to which the message was submitted. If the service worker is not
-          currently running, the worker is started to enable delivery.
+          A <a>push message</a> is delivered to the [= service worker registration/active worker =]
+          associated with the <a>push subscription</a> to which the message was submitted. If the
+          service worker is not currently running, the worker is started to enable delivery.
         </p>
       </section>
       <section>
@@ -583,8 +583,9 @@ <h2>
         <li>Let <var>registration</var> be the <a>PushManager</a>'s associated <a>service worker
         registration</a>.
         </li>
-        <li>If <var>registration</var>'s <a>active worker</a> is null, reject <var>promise</var>
-        with a {{DOMException}} whose name is "{{InvalidStateError}}" and terminate these steps.
+        <li>If <var>registration</var>'s [= service worker registration/active worker =] is null,
+        reject <var>promise</var> with a {{DOMException}} whose name is "{{InvalidStateError}}" and
+        terminate these steps.
         </li>
         <li>Ask the user whether they allow the web application to receive <a>push messages</a>,
         unless a prearranged trust relationship applies or the user has already granted or denied
@@ -1146,8 +1147,8 @@ <h2>
               Then run the following steps in parallel, with <var>dispatchedEvent</var>:
             </p>
             <ol>
-              <li>Wait for all of the promises in the <a>extend lifetime promises</a> of
-              <var>dispatchedEvent</var> to resolve.
+              <li>Wait for all of the promises in the [= ExtendableEvent/extend lifetime promises
+              =] of <var>dispatchedEvent</var> to resolve.
               </li>
               <li>If all the promises resolve successfully, acknowledge the receipt of the <a>push
               message</a> according to [[RFC8030]] and abort these steps.