restore max-width 100% for images

docs/assets/css/bootstrap.css

@@ -57,6 +57,7 @@ sub {
   bottom: -0.25em;
 }
 img {
+  max-width: 100%;
   height: auto;
   border: 0;
   -ms-interpolation-mode: bicubic;

less/reset.less

@@ -75,6 +75,7 @@ sub {
 // -------------------------
 
 img {
+  max-width: 100%; // Make images inherently responsive
   height: auto;
   border: 0;
   -ms-interpolation-mode: bicubic;