Update model docs for device components

docs/models/dcim/modulebay.md

@@ -1,3 +1,24 @@
-## Module Bays
+# Module Bays
 
-Module bays represent a space or slot within a device in which a field-replaceable module may be installed. A common example is that of a chassis-based switch such as the Cisco Nexus 9000 or Juniper EX9200. Modules in turn hold additional components that become available to the parent device.
+Module bays represent a space or slot within a device in which a field-replaceable [module](./module.md) may be installed. A common example is that of a chassis-based switch such as the Cisco Nexus 9000 or Juniper EX9200. Modules in turn hold additional components that become available to the parent device.
+
+!!! note
+    If you need to model child devices rather than modules, use a [device bay](./devicebay.md) instead.
+
+## Fields
+
+### Device
+
+The device to which this module bay belongs.
+
+### Name
+
+The module bay's name. Must be unique to the parent device.
+
+### Label
+
+An alternative physical label identifying the module bay.
+
+### Position
+
+The numeric position in which this module bay is situated. For example, this would be the number assigned to a slot within a chassis-based switch.