fix block pages layout card image

assets/sass/_theme/blocks/pages.sass

@@ -99,6 +99,8 @@
                 margin-left: -$spacing1
                 margin-right: -$spacing1
                 margin-top: -$spacing1
+                img
+                    min-width: 100%
             .more
                 @include arrow-right-hover
                 @include link($block-pages-card-page-color)