Remove CM6 banner, add more subtle link

Author: marijnh

index.html

@@ -22,17 +22,14 @@
   .banner div { margin: 0 auto; max-width: 700px; text-align: center; }
 </style>
 
-<div class=banner><div>
-  CodeMirror is evolving! Check out our <a href="https://codemirror.net/6/">announcement</a> about the upcoming redesigned, accessible, mobile-friendly version.
-</div></div>
-
 <div id=nav>
   <a href="https://codemirror.net"><h1>CodeMirror</h1><img id=logo src="doc/logo.png"></a>
 
   <ul>
     <li><a class=active data-default="true" href="#description">Home</a>
     <li><a href="doc/manual.html">Manual</a>
     <li><a href="https://github.com/codemirror/codemirror">Code</a>
+    <li><a href="https://codemirror.net/6/">Version 6</a>
   </ul>
   <ul>
     <li><a href="#features">Features</a>