r/frigate: Add role to deploy Frigate

Frigate is an NVR that uses machine learning to detect objects on camera
in real time.  It integrates with Home Assistant to expose sensors which
can be used for automation, etc.

The only official way to deploy Frigate is with a container, so we use
Podman and systemd to manage it.

roles/frigate/defaults/main.yml

@@ -0,0 +1,7 @@
+frigate_image_tag: '{{ frigate_default_image_tag }}'
+frigate_mqtt:
+  host: localhost
+frigate_detectors:
+  cpu:
+    type: cpu
+frigate_cameras: {}