fix: make the field label a heading

Refs: #452

web/themes/custom/opdavies/templates/field--node--field-events.html.twig

@@ -39,6 +39,7 @@
 {%
   set title_classes = [
     label_display == 'visually_hidden' ? 'visually-hidden',
+    'mb-2'
   ]
 %}
 
@@ -56,7 +57,7 @@
   {% endif %}
 {% else %}
   <div{{ attributes }}>
-    <div{{ title_attributes.addClass(title_classes) }}>{{ label }}</div>
+    <h2{{ title_attributes.addClass(title_classes) }}>{{ label }}</h2>
     {% if multiple %}
       <ul>
     {% endif %}