Update README.md

Author: civitaspo

README.md

@@ -1,26 +1,40 @@
 # Hdfs output plugin for Embulk
 
-TODO: Write short description here and build.gradle file.
+A File Output Plugin for Embulk to write HDFS.
 
 ## Overview
 
-* **Plugin type**: output
+* **Plugin type**: file output
 * **Load all or nothing**: no
 * **Resume supported**: no
-* **Cleanup supported**: yes
+* **Cleanup supported**: no
 
 ## Configuration
 
-- **property1**: description (string, required)
-- **property2**: description (integer, default: default-value)
+- **config_files** list of paths to Hadoop's configuration files (array of strings, default: `[]`)
+- **config** overwrites configuration parameters (hash, default: `{}`)
+- **output_path** the path finally stored files. (string, default: `"/tmp/embulk.output.hdfs_output.%Y%m%d_%s"`)
+- **working_path** the path temporary stored files. (string, default: `"/tmp/embulk.working.hdfs_output.%Y%m%d_%s"`)
 
 ## Example
 
 ```yaml
 out:
   type: hdfs
-  property1: example1
-  property2: example2
+  config_files:
+    - /etc/hadoop/conf/core-site.xml
+    - /etc/hadoop/conf/hdfs-site.xml
+    - /etc/hadoop/conf/mapred-site.xml
+    - /etc/hadoop/conf/yarn-site.xml
+  config:
+    fs.defaultFS: 'hdfs://hdp-nn1:8020'
+    dfs.replication: 1
+    mapreduce.client.submit.file.replication: 1
+    fs.hdfs.impl: 'org.apache.hadoop.hdfs.DistributedFileSystem'
+    fs.file.impl: 'org.apache.hadoop.fs.LocalFileSystem'
+  formatter:
+    type: csv
+    encoding: UTF-8
 ```
 
 
@@ -29,3 +43,10 @@ out:
 ```
 $ ./gradlew gem
 ```
+
+## Development
+
+```
+$ ./gradlew classpath
+$ bundle exec embulk run -I lib example.yml
+```