Submitit ask-tell tutorial (#2127)

Summary:
Adds a tutorial that shows how to use the AxClient to schedule jobs and tune parameters on a Slurm cluster via SubmitIt.

Code changes:
1. The tutorial notebook
2. Linking the tutorial notebook for the website. (index.js, tutorials.json)

Testing:
Q: How can I make sure that this tutorial shows up correctly on the Ax doc site?

Pull Request resolved: #2127

Reviewed By: mpolson64

Differential Revision: D52700312

Pulled By: mhavasi

fbshipit-source-id: d4cd57427e99ac3b0893cd2bfa91b64510b85876

setup.py

@@ -73,6 +73,7 @@
     "pyro-ppl",  # Required for to call run_inference.
     "pytorch-lightning",  # For the early stopping tutorial.
     "papermill",  # For executing the tutorials.
+    "submitit",  # Required for building the SubmitIt notebook.
 ]