add Domain descriptions

Author: matt-beanland

diffo.livemd

@@ -448,6 +448,6 @@ broadband_0001 |> Jason.encode!(pretty: true) |> IO.puts
 ## What Next?
 
 In this tutorial you've used Diffo to create, relate and update some TMF Service and Resources, simulating activities over the service and resource lifecycle, and you've learned how this functionality is underpinned by open source Neo4j, Ash Framework and Elixir.
-Diffo contain an example Access domain showing how to specialise the structure and behaviour of TMF Services and Resources.
+Diffo contains an example Access domain showing how to specialise the structure and behaviour of TMF Services and Resources.
 
 If you find Diffo useful please visit and star on [github](https://github.com/diffo-dev/diffo/). Feel free to join discussions and raise issues to discuss PR's.

lib/diffo/access/access.ex

@@ -17,6 +17,10 @@ defmodule Diffo.Access do
   alias Diffo.Access.Cable
   alias Diffo.Access.Path
 
+  domain do
+    description "An example showing how TMF Services and Resources for a fictional Access domain can be extended from the Provider domain"
+  end
+
   resources do
     resource DslAccess do
       define :get_dsl_by_id, action: :read, get_by: :id

lib/diffo/provider.ex

@@ -11,6 +11,10 @@ defmodule Diffo.Provider do
   use Ash.Domain,
     otp_app: :diffo
 
+  domain do
+    description "Extensible Ash Resources and API related to Providing TMF Services and Resources"
+  end
+
   resources do
     resource Diffo.Provider.Specification do
       define :create_specification, action: :create