Check security of jeckyll jsonify

[SteveALee]

XSS attacks are potentially possible given some data in text fields is user entered so untrusted..

eg with text </script><script>alert('mwahaha!!')</script>

As a minimum should escape all the unsanitised input text in the liquid templates, eg in HTML using escape or escape_once:

Could also sanitise the input before adding to the JSON file