Fix to LongestEdge readme

Author: Podsiadlo

lonestar/scientific/cpu/longestedge/README.md

@@ -5,7 +5,7 @@ DESCRIPTION
 -----------
 
 This program runs a variant of Rivaras mesh refinement algorithm on portions of the earth's surface.
-It requires the data available at https://dds.cr.usgs.gov/srtm/version2_1/SRTM3/ and can generate `.node`, `.ele.`, and `.mesh` files that follow the same format used in https://www.cs.cmu.edu/~quake/triangle.html.
+It requires the data available at https://dds.cr.usgs.gov/srtm/version2_1/SRTM3/ and can generate `.node`, `.ele.`, and `.poly` files that follow the same format used in https://www.cs.cmu.edu/~quake/triangle.html.
 The command line inputs are the bounds of a box in UTM coordinates.
 
 BUILD