Assign default namespace if not set in manifests

Various helm fixes

Enable systemd ready notification for k3s server

Fix containerd debug log env var

Remove spurious error on start

Disables k8s generic api server systemd ready notification and send
our own ready notification after server available and kubeconfig
available.

Make sure we unset the NOTIFY_SOCKET environment variable by passing
`true` to SdNotify so the agent can start containers.

refactor: creates preloadImages function.

Add --service-cidr and --cluster-dns server args support

Fixup pr165

Document uninstall and Traefik, Helm integration (references #86, #96, #97)

Enforce lower case hostname for node

Fix inconsistent title case

Improve clarity

README: fix typo

preload a docker image on the k3s node agents

Co-Authored-By: juliens <julien.salleyron@gmail.com>

Revert "Enable systemd ready notification for k3s server"

This reverts commit c73e9187.