It is a minor update.
It contains the highlighted syntax and a correction to the generated file when the game is opened on mobile devices.
Download at: https://textadventures.co.uk/squiffy
New Squiffy 5.1.3
Thanks to ByFernanz and krepflap.
Squiffy 5.1.3 is out!
Text Adventures Blog 
Hey, neat. 🙂
By the by, would love a JSON export feature.