Add background-size: cover to articles

Author: Claudio Cortese

_includes/css/agency.css

@@ -1129,6 +1129,7 @@ article p {
     box-shadow: inset 0 0 0 100vw rgba(0,0,0,0.5);
     background-position: center;
     background-repeat: no-repeat;
+    background-size: cover;
     position: relative;
     overflow: hidden;
     transition: box-shadow .25s ease-in-out;