roles/Zigbee2MQTT: Deploy using Podman

Zigbee2MQTT is very similar to ZwaveJS2Mqtt: it is a daemon process that
communicates with the Zigbee radio and integrates with Home Assistant
using MQTT.  Naturally, I decided to deploy it in the same way as
ZwaveJS2Mqtt, using a systemd unit to run it in a container with Podman.

roles/zigbee2mqtt/vars/main.yml

@@ -0,0 +1,10 @@
+zigbee2mqtt_podman_packages:
+- podman
+zigbee2mqtt_config:
+  homeassistant: true
+  permit_join: '{{ zigbee2mqtt_permit_join|bool }}'
+  mqtt: >-
+    {{ zigbee2mqtt_mqtt }}
+  serial:
+    adapter: '{{ zigbee2mqtt_serial_adapter }}'
+    port: '{{ zigbee2mqtt_container_device }}'