Set max-width on Wiki images

Fixes images expanding outside of parent container

services/web/public/stylesheets/app/wiki.less

@@ -13,6 +13,10 @@
 			font-size: 18px;
 		}
 	}
+
+	img {
+		max-width: 100%;
+	}
 	
 	.page-header {
 		a {