✨ Journal: Save Entry#summary when Writing Entries

- zinc-collective#2
- zinc-collective#10

And just like that, there's a `Summary` field on the
`Journal::Entry#new` page!

app/furniture/journal/entries/_form.html.erb

@@ -1,5 +1,7 @@
 <%= form_with model: entry.location, class: "flex flex-col grow" do |f| %>
     <%= render "text_field", { attribute: :headline, form: f} %>
+    <%= render "text_area", { attribute: :summary, form: f} %>
+
     <%= render "text_area", { attribute: :body, form: f, field_classes: "grow", container_classes: "grow flex flex-col"} %>
     <%= render "datetime_field", { attribute: :published_at, form: f} %>
 

app/furniture/journal/entry_policy.rb

@@ -17,7 +17,7 @@ def update?
     end
 
     def permitted_attributes(_params)
-      %i[headline body published_at]
+      %i[headline summary body published_at]
     end
 
     class Scope < ApplicationScope