added support for cover images in lists

exampleSite/content/examples/_index.md

@@ -0,0 +1,19 @@
+---
+title: "Showcase"
+description: "See what's possible with Blowfish."
+
+cascade:
+  showEdit: false
+  showReadingTime: false
+  showSummary: true
+  showLikes: false
+  showViews: false
+---
+
+{{< lead >}}
+See what's possible with Blowfish.
+{{< /lead >}}
+
+This section contains links to example templates and pages created using Blowfish to get you inspired.
+
+---