Preserve line breaks for the instruction fields

src/view/form/AphrontFormView.php

@@ -86,7 +86,9 @@ final class AphrontFormView extends AphrontView {
   public function appendRemarkupInstructions($remarkup) {
     return $this->appendInstructions(
       PhabricatorMarkupEngine::renderOneObject(
-        id(new PhabricatorMarkupOneOff())->setContent($remarkup),
+        id(new PhabricatorMarkupOneOff())
+            ->setContent($remarkup)
+            ->setPReserveLinebreaks(true),
         'default',
         $this->getUser()));
   }