* add pre-commit hook configuration

* add tmp.md to .gitignore

* describe the use of pre-commit hook in CONTRIBUTING.md

* fix docs/integration.md errors identified by markdownlint

* fix docs/<file>.md errors identified by markdownlint

* docs/azure-csi.md
* docs/azure.md
* docs/bootstrap-os.md
* docs/calico.md
* docs/debian.md
* docs/fcos.md
* docs/vagrant.md
* docs/gcp-lb.md
* docs/kubernetes-apps/registry.md
* docs/setting-up-your-first-cluster.md
* docs/vagrant.md
* docs/vars.md

* fix contrib/<file>.md errors identified by markdownlint

* set selinux type t_etc if selinux state is enforcing

* workaround with update repo is no longer needed
remove comments about failing playbook

* grubby is not available in distros using ostree

* remove docker support because removed in fcos
update install script example with live rootfs

* do not call grubby on ostree based distro

* update docs enabling containerd on fedora coreos

* fix upgrade of crio on fcos
- update documents

* install conntrack required by kube-proxy
- like commit 48c41bcb

* enable fedora modular repo for crio

* allow to override crio configuration
- set cgroup manager same to kubelet_cgroup_driver if defined
- path of seccomp_profile depends on distribution

* allow to override crio configuration
- fix path for ubuntu

* allow to override crio configuration
- fix cni path for fcos

* fedora coreos support
- bootstrap and new fact for

* fedora coreos support
- fix bootstrap condition

* fedora coreos support
- allow customize packages for fedora coreos bootstrap

* fedora coreos support
- prevent install ptyhon3 and epel via dnf for fedora coreos

* fedora coreos support
- handle all ostree like os in same way

* fedora coreos support
- handle all ostree like os in same way for crio

* fedora coreos support
- add fcos documentations