Add branch index section to README

Added branch index section to README for clarity on environment branches.

Author: jeffmaki

README.md

@@ -6,6 +6,13 @@ This is a combination API backend for workspaces, providing /workspaces* methods
 the OSM API ("openstreetmap website") plus OSM CGI-map (the C-accelerated methods) that enforces 
 authorization and authentication based on a TDEI/Keycloak JWT token (see main.py for this proxy logic). 
 
+## Branch Index
+
+* ```develop``` do your work here
+* ```development``` keep this up to date with the "development" environment / dev tag
+* ```staging``` keep this up to date with the "staging" environment / stage tag
+* ```production``` keep this up to date with the "production" environment / prod tag
+* 
 ## To start on your local machine for dev work
 
 ```