Updated README.md .

README.md

@@ -18,6 +18,17 @@ stl_dump.py <file.geo>
 
 Dumps all the meshes contained in <file.geo> to <geo_name>/<model_name.stl>. <geo_name> and <model_name> are read from the .geo.
 
+## geo_edit.py
+A command line tool for modifying a .geo file
 
-##Known issues:
+geo_edit.py <infile.geo> <outfile.geo> <operation> [<operation options> ...]
- - Not all structures are regenerated when writing a .geo file. (PolyGrid and Reductions)
+
+Operation                   | Description
+--------------------------- | ---------------------------
+  del_model <reg_ex>  | Deletes all models whose name contains the regular expression <reg_ex>.
+  geo_name <name>     | Change the .geo's name to <name>.
+
+Multiple operations can be specified and performed in the same run.
+
+## Known Issues
+ - Not all structures are regenerated when writing a .geo file. (Reductions)