add story for field description

priv/storybook/components/field_description.story.exs

@@ -0,0 +1,21 @@
+defmodule Storybook.Components.FieldDescription do
+  use PhoenixStorybook.Story, :component
+
+  def function, do: &Doggo.field_description/1
+
+  def variations do
+    [
+      %Variation{
+        id: :default,
+        attributes: %{for: "user_name"},
+        slots: [
+          """
+          <:description>
+            only lowercase letters and numbers, max. 30 characters
+          </:description>
+          """
+        ]
+      }
+    ]
+  end
+end