move our header to the top for visibility, and linkj back to the original make_GLM_grids script

gridded_glm/bin/_make_glm_grids.py

 #!/usr/bin/env python3
+# Based on https://github.com/deeplycloudy/glmtools/blob/master/examples/grid/make_GLM_grids.py
+
+parse_desc = """Grid GLM flash data.
+
+The start and end times can be specified
+independently, or if not provided they will be inferred from the filenames.
+
+Grid spacing is regular in latitude and longitude with the grid box
+being sized to match the requested dx, dy at the center of the grid.
+
+By default, data will be saved to the current directory according to the
+standard GOES imagery naming convention. This behavior can be fully controlled
+by adjusting the -o argument.
+"""
 
 import numpy as np
 from datetime import datetime
@@ -14,19 +28,6 @@ import logging
 
 log = logging.getLogger(__name__)
 
-parse_desc = """Grid GLM flash data.
-
-The start and end times can be specified
-independently, or if not provided they will be inferred from the filenames.
-
-Grid spacing is regular in latitude and longitude with the grid box
-being sized to match the requested dx, dy at the center of the grid.
-
-Therefore, this script can be used to process multiple days and they will
-be written to a standardized directory structure.
-"""
-
-
 def create_parser():
     import argparse
     parser = argparse.ArgumentParser(description=parse_desc)