README.md in tarzan-0.0.2 vs README.md in tarzan-0.0.3

@@ -20,9 +20,11 @@
 
 From the command line run:
 
     $ tarzan
 
+To use Campfire as an interface, define the following environment variables: `CAMPFIRE_SUBDOMAIN`, `CAMPFIRE_ROOM_ID` and `CAMPFIRE_TOKEN`.
+
 ## Contributing
 
 1. Fork it ( http://github.com/claudiob/tarzan/fork )
 2. Create your feature branch (`git checkout -b my-new-feature`)
 3. Commit your changes (`git commit -am 'Add some feature'`)