fix(security): upgrade jQuery to v3.5.1 (#249)

This fixes several [vulnerabilities][0] that are present in the currently used jQuery 3.2.1.

[0]: https://snyk.io/test/npm/jquery/3.2.1

Author: Piccirello

public/jquery.min.js

@@ -60,7 +60,7 @@
 
     <input type="hidden" id="basePath" value="{{ basePath }}">
     {{#if (useCdn)}}
-    <script type="text/javascript" src="//cdn.jsdelivr.net/g/jquery@3.2.1,bootstrap@3.3.7"></script>
+    <script type="text/javascript" src="//cdn.jsdelivr.net/g/jquery@3.5.1,bootstrap@3.3.7"></script>
     {{else}}
     <script type="text/javascript" src="{{ basePath }}/jquery.min.js"></script>
     <script type="text/javascript" src="{{ basePath }}/bootstrap.min.js"></script>