website: Add links for tutorial/workshop

Add link for the youtube livestreams and to the slides for the tutorial.

Signed-off-by: Jason Lowe-Power <jason@lowepower.com>
Change-Id: I9f63a5a72acd92205ab4db3cb31b9a8bd8e739ba
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5-website/+/60689
Tested-by: Bobby Bruce <bbruce@ucdavis.edu>
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
5 files changed