DevTools: NetworkPanel: show link where resource timing is explained.

Source/devtools/front_end/inspectorStyle.css

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2009 Anthony Ricaud <rik@webkit.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 2808 matching lines @@
 }
 
 .resources-divider-label {
     position: absolute;
     top: 4px;
     right: 3px;
     font-size: 80%;
     white-space: nowrap;
     pointer-events: none;
 }
+
+.link {
+    cursor: pointer;
+    text-decoration: underline;
+    color: rgb(17, 85, 204);
+}