Add descriptions to TodoStateEnum

app/graphql/types/todo_state_enum.rb

@@ -2,7 +2,7 @@
 module Types
   class TodoStateEnum < BaseEnum
-    value 'pending'
-    value 'done'
+    value 'pending', description: "The state of the todo is pending."
+    value 'done', description: "The state of the todo is done."
   end
 end

doc/api/graphql/reference/index.md

@@ -5629,8 +5629,8 @@ State of a test report.
 | Value | Description |
 | ----- | ----------- |
-| `done` |  |
-| `pending` |  |
+| `done` | The state of the todo is done. |
+| `pending` | The state of the todo is pending. |
 ### TodoTargetEnum