Update README.md

Author: spancer

README.md

@@ -1,6 +1,9 @@
 # Bigdata with docker compose
 Deploy big data components using docker compose, you can use docker to set up hadoop based big data platform in a few minutes, docker images include Hadoop 3+, HBase 2+, Hive 3+, Kafka 2+, Prestodb 0.247+, Flink 1.11+, ELK 7.9+ ,etc. Integration tests between Hadoop and Hive,  Hadoop and HBase, Flink on yarn, Prestodb against Kafka, Elasticsearch, HBase, Hive had been covered. You can used it in development evironment to test your applications, but it's not recommended to use in production.
 
+## How to build ?
+Docker build files are holded [here](https://github.com/spancer/bigdata-docker-builds.git), you can folk and custom it as needed.
+
 ## Supported components
 
 * Apache Hadoop 3.2