make change message permanent

app/views/merged/changes/index.haml

@@ -4,6 +4,13 @@
   .text-xl.text-gray-900
     Branch
     = branch
+-if flash.notice
+  .m-20.rounded-xl.border.border-gray-100.p-4.shadow-xl
+    .flex-1
+      %strong.block.font-medium.text-gray-900 Ok
+      %p.mt-1.text-sm.text-gray-700
+        = markdown flash.notice
+
 .overflow-hidden.overflow-x-auto.rounded-lg.border.border-gray-200.m-20
   %table.min-w-full.divide-y.divide-gray-200.text-sm
     %thead.bg-gray-100