Update debian.md

Fixed anchor links for Jessie/Wheezy (broken on docs.docker.com)

Update debian.md

Signed-off-by: Scott Stamp <scott@hypermine.com>
add Scott's link checker script, and fix what it finds

Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au>
Merge pull request #9682 from SvenDowideit/scottstamp-stale-links-pr-carry

Scottstamp stale links pr carry