style: Don't highlight links when they are in headers

This uses some SASS magic instead of the previous single rule
because I need it for both the blog title as well as each post's
title link. Yay, SASS?!

source/scss/main.scss

@@ -25,6 +25,10 @@ h5, .h5,
 h6, .h6 {
   font-weight: normal;
   color: #333;
+  a, a:hover, a:focus {
+    color: inherit;
+    text-decoration: none;
+  }
 }
 
 
@@ -94,11 +98,6 @@ h6, .h6 {
   font-size: 2rem;
   font-weight: normal;
 }
-.blog-title a,
-.blog-title a:hover,
-.blog-title a:focus {
-  color: inherit;
-}
 .blog-description {
   font-size: 1.1rem;
   color: #999;