Site: Don't allow the img to be larger than the containing obj. [ci skip]

/cc @penibelst

site/_includes/css/style.css

@@ -590,6 +590,10 @@ article h2:first-child {
   filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#9e2812', endColorstr='#6f0d0d',GradientType=0 );
 }
 
+.post-content img {
+  max-width: 100%
+}
+
 .label {
   float: left;
   text-transform: uppercase;