studio - syncing cheatsheet language with new class name for heading 1 again

cms/templates/widgets/problem-edit.html

@@ -35,7 +35,7 @@
         <div class="cheatsheet-wrapper">
             <div class="row">
                 <h6>Heading 1</h6>
-                <div class="col sample header">
+                <div class="col sample heading-1">
                     <img src="/static/img/header-example.png" />
                 </div>
                 <div class="col">