Update readme

README.md

@@ -84,5 +84,21 @@ C:\Python27\ArcGIS10.5\python plot_heatmaps.py param-files\survey-2-avoca.yaml
 
 Example usage:
 ```
-python extract_contours.py 
-```
+python extract_contours.py
+```
+
+## polyline_to_points.py
+This script interpolates points along transects in a shapefile.
+
+Example usage:
+
+```
+# Extract points at default spacing (1m)
+$ python polyline_to_points.py path/to/shp
+
+# Extract points at 5m increments
+$ python polyline_to_points.py -s 5 path/to/shp
+
+# Use profile names from field "ProfileID"
+$ python polyline_to_points.py -f ProfileID path/to/shp
+```