Update readme to reflect new scripts

Author: ishaan95

README.md

@@ -2,5 +2,6 @@
 Generate and load dataset of road network maps.
 
 # Quick start
-* Use requirements file to install pip packages.
-* Run `maps.py` script. It will generate many PIL Image objects. 
+* Use pip to install necessary python packages `pip install -r requirements.txt`.
+* Run `python run.py` script. It will store .dill files in the data/output/ directory. 
+* These dill files can be read using the `ImgGroupReader` object in `read.py`. Run `read.py` to run a small test for the same.