add a comment to the config file about the support keys

config/config.example.js

@@ -64,6 +64,19 @@ module.exports = {
         //"https://my.awesome.website/user/#/1/cryptpad-user1/YZgXQxKR0Rcb6r6CmxHPdAGLVludrAF2lEnkbx1vVOo=",
     ],
 
+    /*  CryptPad's administration panel includes a "support" tab
+     *  wherein administrators with a secret key can view messages
+     *  sent from users via the encrypted forms on the /support/ page
+     *
+     *  To enable this functionality:
+     *    run `node ./scripts/generate-admin-keys.js`
+     *    save the public key in your config in the value below
+     *    add the private key via the admin panel
+     *    and back it up in a secure manner
+     *
+     */
+    // supportMailboxPublicKey: "",
+
     /* =====================
      *      Infra setup
      * ===================== */