Merge pull request rancher#375 from dweomer/pre-v0.9.0

doc cleanup prior to release

Merge pull request rancher#371 from dweomer/udev-trigger

udev-trigger as sysinit service

Merge pull request rancher#369 from dweomer/deprecate-upgrade-scripts

deprecate upgrade scripts in favor of upgrade controller

Merge pull request rancher#363 from dweomer/eudev

udev support

Merge pull request rancher#362 from dweomer/k3s/v1.17.2+k3s1

k3s: v1.17.2+k3s1

Merge pull request rancher#355 from dweomer/linuxkit/metadata/hetzner

update linuxkit/metadata supporting hetzner

Merge pull request rancher#327 from dweomer/fix-upgrade-scripts

fix the upgrade scripts

Merge pull request rancher#325 from dweomer/package/docker-fix

make drone happy so it will publish images

Merge pull request rancher#323 from dweomer/package/docker

package: build and publish docker images

Merge pull request rancher#321 from dweomer/ssh-config

sshd_config: establish default values in overlay