Add page header

app/views/form/page.html.erb

@@ -6,6 +6,9 @@
 <% end %>
 
 <%= turbo_frame_tag "case_log_form", target: "_top" do %>
+  <h1 class="govuk-heading-xl">
+    <%= page_info["header"] %>
+  </h1>
   <%= form_with action: '/case_logs', method: "next_page", builder: GOVUKDesignSystemFormBuilder::FormBuilder do |f| %>
     <% page_info["questions"].map do |question_key, question| %>
       <%= render partial: "form/#{question["type"]}_question", locals: { case_log_id: case_log_id, question_key: question_key, question: question, f: f } %>