Am interface to filter platforms (ios/android)

Not sure what the UI would look like but there needs to be some sort of way to filter the items by platform.

Maybe like how github search works, or maybe there's a better way. Need to investigate and build

No files or tests are named. Start by locating the existing browsing and search UI for the Jason Registry, then investigate how extensions expose their iOS or Android platforms and decide how filtering should work. Done is not defined until the UI and expected filter behavior are specified and implemented.

Written by the indexing model from the issue text.