chore: tidy up index.html (#379)

Co-authored-by: yoavweiss <[email protected]>

Author: github-actions[bot]

index.html

@@ -759,9 +759,9 @@ <h3>
           response</a>.
         </p>
         <p data-dfn-for="PerformanceResourceTiming">
-          The <dfn>contentType</dfn> getter steps are to return
-          <a>this</a>'s <a data-for="PerformanceResourceTiming">resource
-          info</a>'s [=response body info/content type=].
+          The <dfn>contentType</dfn> getter steps are to return <a>this</a>'s
+          <a data-for="PerformanceResourceTiming">resource info</a>'s
+          [=response body info/content type=].
         </p>
         <p data-dfn-for="PerformanceResourceTiming">
           The <dfn>renderBlockingStatus</dfn> getter steps are to return