Add demos

demo-1.yml

+- name: Install Prometheus
+  hosts: frontend
+  tasks:
+  - name: Make sure timesyncd is installed
+    ansible.builtin.apt:
+      name: systemd-timesyncd
+      state: present
+  - name: Make sure timesyncd is started on boot
+    ansible.builtin.systemd:
+      name: systemd-timesyncd.service
+      state: started
+      enabled: true

demo-2.yml

+- name: Download Go
+  hosts: frontend
+  vars:
+    go_version: "1.19.3"
+  tasks:
+  - name: Download Go version {{go_version}}
+    ansible.builtin.get_url:
+      url: https://go.dev/dl/go{{go_version}}.linux-amd64.tar.gz
+      dest: /tmp/go{{go_version}}.linux-amd64.tar.gz