feat: add link to GitHub statistics from deployments page (#1215)

This uses https://github.com/jgehrcke/github-repo-stats so that we can
track usage beyond the 14 day window provided by GitHub.

Signed-off-by: Derek Hower <[email protected]>

Author: dhower-qc

tools/scripts/pages.html.erb

@@ -156,6 +156,7 @@
           <h3>Repository development</h3>
           <ul>
             <li><a href="<%= ENV["PAGES_URL"] %>/reuse_bom.txt">Reuse Bill of Materials (LICENSE information)</a></li>
+            <li><a href="https://dhower-qc.github.io/udb-stats/riscv-software-src/riscv-unified-db/latest-report/report.html">GitHub usage statistics (updated daily)</a></li>
           </ul>
         </div>
       </div>