0707: added ref link

user.js

@@ -471,7 +471,8 @@ user_pref("network.proxy.autoconfig_url.include_path", false); // default: false
  * TRR = Trusted Recursive Resolver
  * .mode: 0=off, 1=race, 2=TRR first, 3=TRR only, 4=race for stats, but always use native result
  * [WARNING] DoH bypasses hosts and gives info to yet another party (e.g. Cloudflare)
- * [1] https://www.ghacks.net/2018/04/02/configure-dns-over-https-in-firefox/ ***/
+ * [1] https://www.ghacks.net/2018/04/02/configure-dns-over-https-in-firefox/
+ * [2] https://hacks.mozilla.org/2018/05/a-cartoon-intro-to-dns-over-https/ ***/
    // user_pref("network.trr.mode", 0);
    // user_pref("network.trr.bootstrapAddress", "");
    // user_pref("network.trr.uri", "");