fixup! fix(aio): remove heading border

Author: petebacondarwin

Diff for: aio/src/styles/0-base/_typography.scss

@@ -50,13 +50,7 @@ h6 {
   clear: both;
 }
 
-h1 {
-  @media screen and (max-width: 600px) {
-    margin: 0;
-  }
-}
-
-h1:after, h2, h3, h4, h5, h6 {
+h1, h2, h3, h4, h5, h6 {
   @media screen and (max-width: 600px) {
     margin: 8px 0;
   }

Diff for: aio/src/styles/1-layouts/_marketing-layout.scss

@@ -20,10 +20,6 @@
     transform: none;
   }
 
-  h1:after {
-   content: none;
-  }
-
   .hero-title {
     display: inline-block;
     font-size: 28px;