[Doc] Better formatting in autograd.rst (#72586)
Summary:
See title.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/72586
Reviewed By: soulitzer
Differential Revision: D34177704
Pulled By: albanD
fbshipit-source-id: 1adf6ebed4f64ec4d8fff160df300c8e6ee528ea
(cherry picked from commit bbb586d67d726430e91f07bf55e2272381cadd1f)
