Prerender report pages (#893)

* prerender report pages

* eager prefetch, moderate prerender

* list

* Simplify approach

---------

Co-authored-by: Barry Pollard <barrypollard@google.com>
Co-authored-by: Barry Pollard <barry_pollard@hotmail.com>

Author: rviscomi

templates/base.html

@@ -35,6 +35,22 @@
     {% block scripts %}
     <script defer src="{{ get_versioned_filename('/static/js/web-vitals.js') }}" nonce="{{ csp_nonce() }}"></script>
     <script defer src="{{ get_versioned_filename('/static/js/send-web-vitals.js') }}" nonce="{{ csp_nonce() }}"></script>
+    <script type="speculationrules" nonce="{{ csp_nonce() }}">
+      {
+        "prefetch": [{
+          "where": {
+            "href_matches": "/reports/*"
+          },
+          "eagerness": "eager"
+        }],
+        "prerender": [{
+          "where": {
+            "href_matches": "/*"
+          },
+          "eagerness": "moderate"
+        }]
+      }
+    </script>
     {% endblock %}
   </body>
 </html>