Nicely stylize links in code blocks

This is mostly for Agda rendering.

Signed-off-by: Danila Fedorin <danila.fedorin@gmail.com>

assets/scss/code.scss

@@ -39,6 +39,15 @@ pre code {
         overflow: auto;
         margin-bottom: 1rem;
 
+        a {
+          color: inherit;
+          border: none;
+
+          &:hover, &:focus {
+            background-color: rgba($primary-color, 0.25);
+          }
+        }
+
         td {
             padding: 0;
         }