add some links to the tutorial index and between chapters.

llvm-svn: 43730
diff --git a/llvm/docs/tutorial/LangImpl6.html b/llvm/docs/tutorial/LangImpl6.html
index 978ba8e..b113afc 100644
--- a/llvm/docs/tutorial/LangImpl6.html
+++ b/llvm/docs/tutorial/LangImpl6.html
@@ -14,6 +14,7 @@
 <div class="doc_title">Kaleidoscope: Extending the Language: User-defined Operators</div>
 
 <ul>
+<li><a href="index.html">Up to Tutorial Index</a></li>
 <li>Chapter 6
   <ol>
     <li><a href="#intro">Chapter 6 Introduction</a></li>
@@ -24,6 +25,8 @@
     <li><a href="#code">Full Code Listing</a></li>
   </ol>
 </li>
+<li><a href="LangImpl7.html">Chapter 7</a>: Extending the Language: Mutable
+Variables / SSA Construction</li>
 </ul>
 
 <div class="doc_author">