refactor: yml -> yaml

Signed-off-by: Tuan-Dat Tran <tuan-dat.tran@tudattr.dev>

roles/docker_host/tasks/30_user_group_setup.yaml

@@ -0,0 +1,16 @@
+---
+- name: Ensure group "docker" exists
+  ansible.builtin.group:
+    name: docker
+    state: present
+  become: true
+
+- name: Append the group docker to "{{ ansible_user_id }}"
+  ansible.builtin.user:
+    name: "{{ ansible_user_id }}"
+    shell: /bin/bash
+    groups: docker
+    append: true
+  become: true
+  notify:
+    - Restart host