Add new command to readme

README.md

@@ -52,7 +52,7 @@ To invoke the CLI using the virtual environment and from within the `src` folder
 ```
 pipenv run python -m lascli <group> <command> <options>
 ```
-Available groups are `fileload`, `ingest`, `list` and `download`. Help can be obtained with the `-h` option.
+Available groups are `fileload`, `ingest`, `list`, `update` and `download`. Help can be obtained with the `-h` option.
 ```
 pipenv run python -m lascli -h
 pipenv run python -m lascli fileload -h