Update documentation.

README.md

@@ -80,7 +80,7 @@ pipenv run ./gh2jira sync
 ```
 
 Note: Instead of the `--gh-token` and `--jira-token` options, you may also set the `GH2JIRA_GH_TOKEN` and `GH2JIRA_JIRA_TOKEN` environment variables.
-The above command could be invoked via a cronjob every X minutes, to make sure issues and alerts are kept in sync. Currently, two-way integration is not yet possible via this command. If you need it, use the CLI's `serve` command (see below).
+The above command could be invoked via a cronjob every X minutes, to make sure issues and alerts are kept in sync. To allow two-way integration (via `--direction both`) you have to provide a states file via `--states-file states.json`. The CLI will create that file, if it doesn't exist!
 
 ## Using the CLI's `serve` command
 

cli.py

@@ -247,7 +247,8 @@ def main():
     )
     sync_parser.add_argument(
         '--states-file',
-        help='File holding the current states.',
+        help='File holding the current states of all alerts. The program will create the' +
+             ' file if it doesn\'t exist and update it after each run.',
         default=None
     )
     sync_parser.set_defaults(func=sync)