add default user signatures

app/views/start_form/show.html.erb

@@ -20,7 +20,7 @@
     <%= form_for @submitter, url: start_form_path(@template.slug), data: { turbo_frame: :_top }, method: :put, html: { class: 'space-y-4' } do |f| %>
       <div class="form-control !mt-0">
         <%= f.label :email, class: 'label' %>
-        <%= f.email_field :email, required: true, class: 'base-input', placeholder: 'Provide your email to start' %>
+        <%= f.email_field :email, value: current_user&.email, required: true, class: 'base-input', placeholder: 'Provide your email to start' %>
       </div>
       <div class="form-control">
         <%= f.button button_title(title: 'Start', disabled_with: 'Starting'), class: 'base-button' %>