We've been getting reports from users that our Freshdesk webhook
isn't working correctly. It turns out that the issue had nothing
to do with the webhook implementation itself!
In freshdesk/doc.md, we have a JSON template we ask users to
copy/paste into a textbox in the Freshdesk UI. That JSON template
contains "{{" and "}}" characters which we escaped as Unicode
decimals to prevent clashes with Jinja2 syntax in other parts
of the same template. This worked for a while!
But thanks to the changes introduced as part of the
nested_code_blocks extension, such escaped characters were never
decoded, leading users to copy/paste the same template but with
raw escaped unicode representations of "{{" and "}}" inside. And
that eventually broke our webhook implementation.
This commit makes sure that such characters are properly "unescaped",
just for Freshdesk docs.