Suggest avoiding new environments

Inspired by https://12factor.net/config

Author: runephilosof-abtion

configuration.rst

@@ -544,6 +544,10 @@ going to production:
     It's common for environments to be similar to each other, so you can
     use `symbolic links`_ between ``config/packages/<environment-name>/``
     directories to reuse the same configuration.
+    
+    There are benefits to separating configuration from code. So try to avoid
+    creating new environments and instead set environment variables.
+    This way it is easy to add another environment for staging/qa/review apps.
 
 .. _config-env-vars: