Use var for compatibility

Author: RDIL

mkdocs_git_revision_date_localized_plugin/plugin.py

@@ -77,8 +77,8 @@ def on_post_page(self, output_content, **kwargs):
           <script src="https://cdnjs.cloudflare.com/ajax/libs/timeago.js/4.0.0-beta.2/timeago.min.js"></script>
           <script src="https://cdnjs.cloudflare.com/ajax/libs/timeago.js/4.0.0-beta.2/timeago.locales.min.js"></script>
           <script>
-            const nodes = document.querySelectorAll('.timeago');
-            const locale = nodes[0].getAttribute('locale');
+            var nodes = document.querySelectorAll('.timeago');
+            var locale = nodes[0].getAttribute('locale');
             timeago.render(nodes, locale);
           </script>
         """