s3: fix location create command

Author: Pablo Panero

docs/extensions/s3.md

@@ -22,7 +22,7 @@ Now you need to tell InvenioRDM where that bucket is. For that, create a new loc
 
 ``` console
 $ cd path/to/your/instance
-$ pipenv run invenio files location s3-default s3://default-bucket --default
+$ pipenv run invenio files location create s3-default s3://default-bucket --default
 ```
 
 If you are running the containerized version, run: