website: Added hack-back to gem5-resources page

Change-Id: I6b0bca40f490a944350732f594a567f3f7e4acda
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5-website/+/37737
Reviewed-by: Hoa Nguyen <hoanguyen@ucdavis.edu>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: Bobby R. Bruce <bbruce@ucdavis.edu>
1 file changed