chore: tidy up index.html (#388)

Co-authored-by: noamr <noamr@users.noreply.github.com>

index.html

@@ -322,10 +322,10 @@ <h3>
           <li>If an HTML <code>IMG</code> element has a <code><a href=
           "https://tools.ietf.org/html/rfc2397">data: URI</a></code> as its
           source [[RFC2397]], then this resource will not be included as a <a>
-          PerformanceResourceTiming</a> object in the <a data-cite=
-          "PERFORMANCE-TIMELINE-2#performance-timeline">Performance
-          Timeline</a>. <a>PerformanceResourceTiming</a> entries are only reported for
-          [=http(s) scheme|http(s)=] resources.
+            PerformanceResourceTiming</a> object in the <a data-cite=
+            "PERFORMANCE-TIMELINE-2#performance-timeline">Performance
+            Timeline</a>. <a>PerformanceResourceTiming</a> entries are only
+            reported for [=http(s) scheme|http(s)=] resources.
           </li>
           <li>If a resource <a data-cite="FETCH#concept-fetch">fetch</a> was
           aborted due to a networking error (e.g. DNS, TCP, or TLS error), then