website: Fix the gem5-tutorial-codespace link

This patch changes this into a link instead of plain-text.

Change-Id: I4641dd4626920c6867116c71e21a9fe6e6fb9bc5
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5-website/+/68577
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Tested-by: Bobby Bruce <bbruce@ucdavis.edu>
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
1 file changed