The Perseids Gardener theme uses a widget-friendly version of the Javascript code of the Arethusa treebank editor code to display treebanks.
This code is currently built from the gardener_widget branch of the Arethusa code base. The Gardener repository contains compiled and minimized versions of that code. It can be regenerated by cloning the Arethusa code base, switching to the gardener_widget branch and using the grunt minify:all command. For more information on building Arethusa see the Arethusa README file.
Eventually we would like the widget changes to be merged back into the master branch of the Arethusa repository so that they can be automatically retrieved and built at the time you build your Jekyll publication site.