Documented new behaviour

Author: blootsvoets

README.md

@@ -1,10 +1,17 @@
 # Restructure HDFS files
 
 Build jar from source with
-```
-./gradlew fatJar
+
+```shell
+./gradlew build
 ```
 and find the output JAR file as `build/libs/restructurehdfs-all-0.1-SNAPSHOT.jar`. Then run with:
-```
+
+```shell
 java -jar restructurehdfs-all-0.1-SNAPSHOT.jar <webhdfs_url> <hdfs_topic_path> <output_folder>
 ```
+
+By default, this will output the data in CSV format. If JSON format is preferred, use the following instead:
+```
+java -Dorg.radarcns.format=json -jar restructurehdfs-all-0.1-SNAPSHOT.jar <webhdfs_url> <hdfs_topic_path> <output_folder>
+```