Add tabulate pip install to flight recorder tutorial (#3081)

Don't interrupt user's flow that they may need to install `tabulate`.
Also, show them the actual command that they need to run to install
`tabulate`.

---------

Co-authored-by: Svetlana Karslioglu <svekars@meta.com>

Author: c-p-i-o

prototype_source/flight_recorder_tutorial.rst

@@ -9,7 +9,10 @@ What you will learn
 
 Prerequisites
 -------------
+
 - PyTorch version 2.5 or later.
+- `tabulate <https://pypi.org/project/tabulate/>`__. You can install by running ``pip install tabulate``.
+
 
 Overview
 --------