Update README.md

Describe new repo structure to aid new users

README.md

@@ -4,7 +4,13 @@ Code to quantify the effect of including glacial runoff in Standardized Precipit
 ## Collaborators
 - Sloan Coats (University of Hawaii)
 - Jonathan Mackay (British Geological Survey)
-- Lizz Ultee (Massachusetts Institute of Technology)
+- Lizz Ultee (Middlebury College)
 
 ## What's included
-This repository includes MATLAB code, used to calculate the SPEI for each climate model, scenario, and basin; and Python code, used to analyse the SPEI data.  The Jupyter notebook "SPEI-analysis.ipynb" guides users through an analysis of SPEI mean and variance for any basin of choice.
+This repository includes MATLAB code, used to calculate the SPEI for each climate model, scenario, and basin; and Python code, used to analyse the SPEI data.  The Jupyter notebook "SPEI-analysis.ipynb" guides users through an analysis of SPEI with/without glacial runoff for any basin of choice.
+
+## Organization
+The main repo contains all analysis scripts.  In subfolders are:
+- `archived`: older scripts used to develop parts of the analysis that may have been superseded
+- `data`: all data required to reproduce our results
+- `SPEI_computation`: code used to produce the basin-total SPEI data from output of GCMs and the glacier model