Linking is fine, but a clean UI integration would be better imo. No need for users to leave the app store site then, one can potentially even flash the update from there.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
It does show an update message now - but not a list of improvements. It could easily link to the ChangeLog though