implement amendment signing

app/views/public/amendments/create.html.erb

@@ -0,0 +1,3 @@
+<% message = local_assigns[:already_signed] ? t('.amendment_already_signed_message') : t('.amendment_signed_message') %>
+<% alert_type = local_assigns[:already_signed] ? "alert-warning" : "alert-success" %>
+<p class="alert <%= alert_type %> p-3 lead text-center"><%= message %></p>

app/views/public/amendments/new.html.erb

@@ -0,0 +1,24 @@
+<div class="card shadow-sm">
+  <div class="card-body">
+    <%= errors_summary_for @release %>
+    <%= bootstrap_form_with model: @release, method: :post, url: public_send("account_project_contract_template_#{@contract_template.release_type}_release_amendments_path"), local: true do |form| %>
+      <%= card_field_set_tag t(".amendment.heading") do %>
+        <p><%= @contract_template.amendment_clause %></p>
+      <% end %>
+
+      <hr>
+
+      <div class="form-row">
+        <%= form.text_field :amendment_signer_name, required: true, wrapper_class: "col-sm-6" %>
+      </div>
+
+      <%= card_field_set_tag t(".signature.heading") do %>
+        <%= render "shared/signature_fields", signature_field: :amendment_signature_base64, form: form %>
+      <% end %>
+
+      <div class="mt-5">
+        <%= form.button t("shared.submit_release_long"), class: "btn btn-block btn-lg btn-success", data: { disable_with: t("shared.disable_with") } %>
+      </div>
+    <% end %>
+  </div>
+</div>