Docs: add content to Domain Model - Host Sets page (#624)

website/content/docs/concepts/domain-model/host-sets.mdx

@@ -9,13 +9,34 @@ description: |-
 # Host Sets
 
 A host set is a resource
-which provides a subset of Hosts
-from the set of Hosts of the Host Catalog it belongs to.
-A Host Set belongs to one and only one Host Catalog.
-A Host Set can contain zero or more Hosts.
-A Host Set can be contained by zero or more Targets.
-Host Set is abstract.
-A Host Set is deleted when the Host Catalog it belongs to is deleted.
-The lifecycle of a Host Set is not tied to the lifecycle of any Targets or Hosts.
+that represents a collection of [hosts][]
+which are considered equivalent
+for the purposes of access control.
+A host set can only include hosts
+from the same [host catalog][] as the host set.
+A [target][] can reference host sets from host catalogs
+which belong to the same [project][] as the target.
 
 ## Attributes
+
+A host set has the following configurable attributes:
+
+- `name` - (optional)
+  If set, the `name` must be unique within the host set's parent [host catalog][].
+
+- `description` - (optional)
+
+## Referenced By
+
+- [Host][]
+- [Host Catalog][]
+- [Target][]
+
+[host catalog]: /docs/concepts/domain-model/host-catalogs
+[host catalogs]: /docs/concepts/domain-model/host-catalogs
+[host]: /docs/concepts/domain-model/hosts
+[hosts]: /docs/concepts/domain-model/hosts
+[project]: /docs/concepts/domain-model/scopes#projects
+[projects]: /docs/concepts/domain-model/scopes#projects
+[target]: /docs/concepts/domain-model/targets
+[targets]: /docs/concepts/domain-model/targets