Add HA option, change to yaml inventory, cleanup

- HA option for multiple server nodes using embedded etcd
- Switch to yaml inventory file for easier editing and combining vars
- Update to full ansible module names
- Change master/node names to server/agent
- Cleanup small linting errors
- Add reboot playbook which staggers reboot to keep HA cluster up
- Move playbooks to playbook directory

Signed-off-by: Derek Nola <derek.nola@suse.com>

inventory-sample.yml

@@ -0,0 +1,21 @@
+---
+k3s_cluster:
+  children:
+    server:
+      hosts:
+        192.16.35.11
+    agent:
+      hosts:
+        192.16.35.12
+        192.16.35.13
+
+  vars:
+    ansible_port: 22
+    ansible_user: debian
+    k3s_version: v1.25.5+k3s2
+    systemd_dir: /etc/systemd/system
+    api_endpoint: "{{ hostvars[groups['server'][0]]['ansible_host'] | default(groups['server'][0]) }}"
+    api_port: 6443
+    extra_server_args: ""
+    extra_server_init_args: ""
+    extra_agent_args: ""