nvr1: Install collectd

Also enabling the `md` plugin, which is disabled by default, to monitor
the software RAID array where Frigate recordings are stored.

nvr1.yaml

@@ -8,6 +8,7 @@ ignition:
     - local: zram.ign
     - local: gasket-driver.ign
     - local: frigate.ign
+    - local: collectd.ign
 
 kernel_arguments:
   should_exist:
@@ -26,3 +27,8 @@ storage:
         [Mount]
         What=/dev/disk/by-label/frigate
         Where=/var/lib/frigate
+  - path: /etc/collectd.d/md.conf
+    mode: 0644
+    contents:
+      inline: |
+        LoadPlugin md