#69 added blue hills hiking gpx data info to /data docs for the built-in map gallery info

Author: RandomFractals

data/README.md

@@ -10,6 +10,7 @@
 | [Georgia Population Map](https://gist.githubusercontent.com/bumbeishvili/fac2b30e3be09259a9b27d8c139b1456/raw/214c8e5b047aa6443a2e18607a216f52e02cfe0b/keplergl.json) | [@bumbeishvili/keplergl.json](https://gist.github.com/bumbeishvili/fac2b30e3be09259a9b27d8c139b1456) | ??? | Georgia Population Map |
 | [USA Airports](https://github.com/RandomFractals/geo-data-viewer/blob/master/data/csv/usa-airports.map.json) | [@RandomFractals/usa-airports.map.json](https://github.com/RandomFractals/geo-data-viewer/blob/master/data/csv/usa-airports.map.json) | [USA Ariports](https://github.com/vega/vega-datasets/blob/master/data/airports.csv) | USA Airports |
 | [USA Counties](https://github.com/RandomFractals/geo-data-viewer/blob/master/data/topojson/usa-albers-counties.topo.json) | [@RandomFractals/usa-albers-counties.topo.json](https://github.com/RandomFractals/geo-data-viewer/blob/master/data/topojson/usa-albers-counties.topo.json) | [USA Counties](https://github.com/deldersveld/topojson/blob/master/countries/united-states/us-albers-counties.json) | USA Counties |
+| [Blue Hills Hiking](https://github.com/mapbox/togeojson/blob/master/test/data/blue_hills.gpx) | [@mapbox/togeojson/blue_hills.gpx](https://github.com/mapbox/togeojson/blob/master/test/data/blue_hills.gpx) | [Blue Hills Hiking](https://github.com/mapbox/togeojson/blob/master/test/data/blue_hills.gpx) | Blue Hills Hiking |
 
 See other kepler.gl maps created by the uber-web dev team: