docs: updated readme

README.md

@@ -20,7 +20,11 @@ The script can be both a shell script or a binary. If the script returns with a
 
 
 ### <img alt="run" src="docs/img/fa/rabbit-fast.svg" height="40" valign="middle" /> Usage of `run`
-Run will clone down multiple repositories. For each of those repositories, the script will be run. If the script finished with a zero exit code, and the script resulted in file changes, a pull request will be created with.
+
+This command will clone down multiple repositories. For each of those repositories, the script will be run in the context of that repository. If the script finished with a zero exit code, and the script resulted in file changes, a pull request will be created with.
+
+The environment variable REPOSITORY_NAME will be set to the name of the repository currently being executed by the script.
+
 ```
 Usage:
   multi-gitter run [script path] [flags]