Add a teaser template for case studies

agaric/templates/layout/node--case-study--teaser.html.twig

@@ -0,0 +1,31 @@
+{# Somewhat ironically, we take away the ability for case studies to be
+   represented by their title paragraph.  Because we *don't* use the title
+   paragraph for the main listings on the front page and the /work page (both of
+   which use the tile view mode, which uses only set regular fields), the use of
+   the title paragraph for search results (and anywhere else we use teasers)
+   would be a surprise— the summary field, while also not used on the listing
+   pages, is at least consistently used across multiple content types.
+
+   See agaric/templates/layout/node--teaser.html.twig for variables.
+#}
+
+<a class="teaser media content" href="{{ url }}">
+
+<div class="media-left">
+  {{ content.field_image }}
+  {% if node.bundle == 'case_study' and content.field_subtitle is not empty %}
+    <p class="byline is-mono">
+      {{ content.field_case_study_subtitle }}
+    </p>
+  {% endif %}
+</div>
+<div class="media-content content">
+  <h3 class="title is-5">{{ label }}</h3>
+  <div class="subtitle is-6">
+    {{ content.field_summary }}
+  </div>
+</div>
+
+</a>
+<!-- Unexpected extra content -->
+{{ content|without('field_body_paragraph', 'field_subtitle', 'field_image', 'field_summary', 'uid', 'created') }}