update cockpit doc page
update cockpit doc page

* Add link to upstream documentation
* Add links to blog post about running as a service

shishir-a412ed/atomic-site,nzwulfin/atomic-site,cdrage/atomic-site,bexelbie/atomic-site,bexelbie/atomic-site,cdrage/atomic-site,bexelbie/atomic-site,cdrage/atomic-site,shishir-a412ed/atomic-site,cdrage/atomic-site,nzwulfin/atomic-site,nzwulfin/atomic-site,nzwulfin/atomic-site,shishir-a412ed/atomic-site,shishir-a412ed/atomic-site,nzwulfin/atomic-site,bexelbie/atomic-site,bexelbie/atomic-site