Update docs links due to 2.19.0 GA
Update docs links due to 2.19.0 GA

dkliban/pulpproject.org,pulp/pulpproject.org,dkliban/pulpproject.org,pulp/pulpproject.org,pulp/pulpproject.org,dkliban/pulpproject.org,bmbouter/pulpproject.org,bmbouter/pulpproject.org,bmbouter/pulpproject.org,dkliban/pulpproject.org,bmbouter/pulpproject.org,pulp/pulpproject.org