Replace links to community docs with links to documentation.suse.com

[fsundermeyer]

https://docs.k3s.io/i -> https://documentation.suse.com/cloudnative/k3s/
https://docs.rke2.io -> https://documentation.suse.com/cloudnative/rke2/
https://longhorn.io/ -> https://documentation.suse.com/cloudnative/storage/
https://fleet.rancher.io -> https://documentation.suse.com/cloudnative/continuous-delivery/
https://open-docs.neuvector.com/ -> https://documentation.suse.com/cloudnative/security/
https://ranchermanager.docs.rancher.com/ -> https://documentation.suse.com/cloudnative/rancher-manager/
https://turtles.docs.rancher.com/ -> https://documentation.suse.com/cloudnative/cluster-api/

Note that links will differ, so search & replace will not work.