Add docker image info to readme

README.md

-# earthquake-srdd
-Small Rapid Data Distribution
+# hazdev-broker
+Small Rapid Data Distribution via a Message Broker
+
+
+
+## Apache Kafka Docker image
+
+Files to build an Apache Kafka docker image are stored in `docker-kafka`.
+
+http://kafka.apache.org/
+
+### To run the image:
+```
+docker run -d --name docker-kafka -p 2181:2181 -p 9092:9092 usgs/docker-kafka
+```
+
+- `-d` - run container in background
+- `--name docker-kafka` assign name to container
+- `-p 2181:2181` expose zookeeper port
+- `-p 9092:9092` expose kafka broker port
+- `usgs/docker-kafka` the image on Docker Hub
+
+
+### To build the image:
+```
+cd docker-kafka
+docker build -t usgs/docker-kafka:latest .
+```