Update README.md to document ee_create_controller_def (#169)

roles/ee_builder/README.md

@@ -59,7 +59,7 @@ Best practice is to use the default images, unless needing to pull from another
 |`ee_pull_collections_from_hub`|true|no|bool|Whether or not to pull collections from a specific hub for use in building an Execution Environment. This will create entries that adds the ansible.cfg file into the EE.||
 |`ee_ah_host`|`ah_host`|no|str|Host to use for ansible config file. Alternative default is to use variable from infra.ah_configuration. Required if `ee_pull_collections_from_hub` is `True`.||
 |`ee_ah_token`|`ah_token`|no|str|Token to use for ansible config file. Alternative default is to use variable from infra.ah_configuration. Required if `ee_pull_collections_from_hub` is `True`.||
-
+|`ee_create_controller_def`|false|no|bool|Option to create the 'controller_execution_environments' definition for use by the infra.controller_configuration role||
 ### Execution environment list
 
 This role takes a list of execution environments to describe a state.