Update getting_started.rst (#2737)

* Update getting_started.rst

* No need to mkdir

With mkdir, the copied folder has structure simulator-example/hello-pt/jobs, while without mkdir, the copied folder has structure simulator-example/jobs

* Update getting_started.rst

* Add hello-pt to the folder structure

---------

Co-authored-by: Sean Yang <[email protected]>

docs/getting_started.rst

@@ -304,7 +304,7 @@ we can install these in the Python virtual environment by running:
 .. code-block:: shell
 
   source nvflare-env/bin/activate
-  python3 -m pip install -r simulator-example/requirements.txt
+  python3 -m pip install -r simulator-example/hello-pt/requirements.txt
 
 If using the Dockerfile above to run in a container, these dependencies have already been installed.