Samples have been migrated to spring-security-samples project, but broken links point to old location, wiki. I corrected in fork, but it is not possible to do PR for a wiki.
Comment From: marcusdacoregio
Thanks for your report @marcospds.
I've updated the links to point to the right location and ran a link checker which didn't report any broken links left. I'm closing this as solved but feel free to discuss if any broken link was left behind.