Move Javadoc StatCounter to the API landing page

JDK 17 Javadoc serves the package index from index.html and redirects
overview-summary.html, so the tracker never ran on /docs/api/.

Author: ejboy

docs/api/index.html

@@ -227,5 +227,15 @@ <h1 class="title"><h1>Scriptella API Documentation</h1></h1>
 </footer>
 </div>
 </div>
+  <!-- StatCounter: Scriptella API documentation project -->
+  <script type="text/javascript">
+    var sc_project=13337472;
+    var sc_invisible=1;
+    var sc_security="d3157fa4";
+  </script>
+  <script type="text/javascript"
+  src="https://www.statcounter.com/counter/counter.js" async></script>
+  <noscript><div class="statcounter"><a title="Web Analytics Made Easy - Statcounter" href="https://statcounter.com/" target="_blank"><img class="statcounter" src="https://c.statcounter.com/13337472/0/d3157fa4/1/" alt="Web Analytics Made Easy - Statcounter" referrerPolicy="no-referrer-when-downgrade"></a></div></noscript>
+  <!-- End of Statcounter Code -->
 </body>
 </html>

docs/api/overview-summary.html

@@ -22,16 +22,5 @@
 </noscript>
 <p><a href="index.html">index.html</a></p>
 </main>
-  <!-- StatCounter: Scriptella API documentation project -->
-  <script type="text/javascript">
-    var sc_project=13337472;
-    var sc_invisible=1;
-    var sc_security="d3157fa4";
-  </script>
-  <script type="text/javascript"
-  src="https://www.statcounter.com/counter/counter.js" async></script>
-  <noscript><div class="statcounter"><a title="Web Analytics Made Easy - Statcounter" href="https://statcounter.com/" target="_blank"><img class="statcounter" src="https://c.statcounter.com/13337472/0/d3157fa4/1/" alt="Web Analytics Made Easy - Statcounter" referrerPolicy="no-referrer-when-downgrade"></a></div></noscript>
-  <!-- End of Statcounter Code -->
-
 </body>
 </html>