Override less Ansible settings (#224)

* Do not escalate privileges by default

* Do not disable host key checking by default

* Do not mute deprecation warnings by default

* Provide ansible.cfg only as an example

The new example file does ONLY contain options that are related to this
playbook.

* Remove explicit inventory path from scripts

The inventory file is specified in ansible.cfg, see README.md.

README.md

@@ -67,6 +67,8 @@ node
 
 If multiple hosts are in the master group, the playbook will automatically set up k3s in [HA mode with etcd](https://rancher.com/docs/k3s/latest/en/installation/ha-embedded/).
 
+Finally, copy `ansible.example.cfg` to `ansible.cfg` and adapt the inventory path to match the files that you just created.
+
 This requires at least k3s version `1.19.1` however the version is configurable by using the `k3s_version` variable.
 
 If needed, you can also edit `inventory/my-cluster/group_vars/all.yml` to match your environment.