Adding listing/descriptions for the imagify and themes examples. (#253)
Adding listing/descriptions for the imagify and themes examples. (#253)

There are a couple of queries about the item for themes:

* I was unclear whether to delete the javascript_apis key or use an empty list - I've used an empty list.
* The macros suggests it would be safe to use HTML formatting in the description, so I have done so to create the list of themes (rather than split them out individually)
mdn/webextensions-examples,mdn/webextensions-examples,mdn/webextensions-examples