Updates instructions for security release blog posts
As per https://gitlab.com/gitlab-com/gl-security/appsec/appsec-team/-/issues/57, we now have a security version of the www-gitlab-com
repository.
This merge request updates the instructions for Application Security engineers creating the blog posts associated with security releases.
We have not actually stepped through this process yet, so there may need to be some updates to this as we go along. I believe the steps listed in this MR cover what needs to happen, but I'm not completely certain about them. I will be soliciting review and feedback from the release managers as well as the AppSec team and am happy to update this as needed.
This also needs the security-release-blog-post issue template MR to be merged, since it references it.
Edited by Andrew Kelly