Merge pull request big-data-europe#20 from big-data-europe/fix-dash

fixed dash instrunctions

README.md

@@ -38,7 +38,7 @@ CORE_CONF corresponds to core-site.xml. fs_defaultFS=hdfs://namenode:8020 will b
 ```
   <property><name>fs.defaultFS</name><value>hdfs://namenode:8020</value></property>
 ```
-To define dash inside a configuration parameter, use double underscore, such as YARN_CONF_yarn_log___aggregation___enable=true (yarn-site.xml):
+To define dash inside a configuration parameter, use triple underscore, such as YARN_CONF_yarn_log___aggregation___enable=true (yarn-site.xml):
 ```
   <property><name>yarn.log-aggregation-enable</name><value>true</value></property>
 ```
@@ -50,4 +50,4 @@ The available configurations are:
 * /etc/hadoop/httpfs-site.xml HTTPFS_CONF
 * /etc/hadoop/kms-site.xml KMS_CONF
 
-If you need to extend some other configuration file, refer to base/entrypoint.sh bash script.
+If you need to extend some other configuration file, refer to base/entrypoint.sh bash script.