Hide post excerpt on detail pages

Author: DiogoRibeiro7

_includes/page__hero.html

@@ -32,7 +32,7 @@
       </h1> -->
       {% if page.tagline %}
         <p class="page__lead">{{ page.tagline | markdownify | remove: "<p>" | remove: "</p>" }}</p>
-      {% elsif page.header.show_overlay_excerpt != false and page.excerpt %}
+      {% elsif page.header.show_overlay_excerpt != false and page.excerpt and page.collection != 'posts' %}
         <p class="page__lead">{{ page.excerpt | markdownify | remove: "<p>" | remove: "</p>" }}</p>
       {% endif %}
       {% include page__meta.html %}