Update README.md

Author: rama-nallamilli

README.md

@@ -1,12 +1,17 @@
 # kafka-promethues-monitoring
 Dockerised example of monitoring Kafka with Prometheus and Grafana.  Requires docker and docker-compose.  
 
+## Pre-Requisites
+* install Docker and Docker Compose - https://docs.docker.com/
+* set KAFKA_ADVERTISED_HOST_NAME in `docker-compose.yml` to match your docker host IP.  (Note: Do not use localhost or 127.0.0.1 as the host ip if you want to run multiple brokers).  See wurstmeister's docker-kafka for more information on configuring Kafka - https://github.com/wurstmeister/kafka-docker
+
 ## Usage
 
 ```
 docker-compose up
 ```
 
-View Prometheus UI `http://$DOCKER_HOST_IP:9090`
+View Prometheus UI - `http://$DOCKER_HOST_IP:9090`
+Grafana UI - `http://$DOCKER_HOST_IP:3000` (admin:admin)
 
-WORK IN PROGRESS
+WORK IN PROGRESS