Public Transit accessible

[gassc]

From @hellonewman:

Can we add a filter to the fish fry map of public transit accessible?

This would be super easy to do using GTFS stop locations
https://transitfeeds.com/p/port-authority-of-allegheny-county/274
and just putting a lil buffer around the stop locations, we consider 1320 feet to be within walking distance of transit (quarter mile).