updated Rainbowstream's Dockerfile w/ command

rainbowstream/Dockerfile

@@ -1,3 +1,12 @@
+# Run Rainbowstream in a container
+#
+#        docker run -it --rm \
+#                -v /etc/localtime:/etc/localtime \
+#                -v $HOME/.rainbow_oauth:/root/.rainbow_oauth \ # mount config files
+#                -v $HOME/.rainbow_config.json:/root/.rainbow_config.json \
+#                --name rainbowstream \
+#                jess/rainbowstream
+#
 FROM python:latest
 MAINTAINER Jessica Frazelle <jess@docker.com>