Add a dev-active readme.

Author: Jen Lampton

config/dev-active/README.md

@@ -0,0 +1,9 @@
+This directory contains the configuration files for a LOCAL COPY
+of your the Backdrop DEMO site.
+
+To move this configuration between environments, contents from this directory
+should be copied into the staging directory, and committed there. They will then
+be pulled onto the target server with the next deply.
+
+To make this configuration active, see
+admin/config/development/configuration/sync on the target server.