docs: Use <Hn> as Heading elements instead of <DIV class="doc_foo">.

H1 ... doc_title
H2 ... doc_section
H3 ... doc_subsection
H4 ... doc_subsubsection

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129736 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/tutorial/LangImpl1.html b/docs/tutorial/LangImpl1.html
index c96cb9f..cc2fa97 100644
--- a/docs/tutorial/LangImpl1.html
+++ b/docs/tutorial/LangImpl1.html
@@ -11,7 +11,7 @@
 
 <body>
 
-<div class="doc_title">Kaleidoscope: Tutorial Introduction and the Lexer</div>
+<h1>Kaleidoscope: Tutorial Introduction and the Lexer</h1>
 
 <ul>
 <li><a href="index.html">Up to Tutorial Index</a></li>
@@ -30,7 +30,7 @@
 </div>
 
 <!-- *********************************************************************** -->
-<div class="doc_section"><a name="intro">Tutorial Introduction</a></div>
+<h2><a name="intro">Tutorial Introduction</a></h2>
 <!-- *********************************************************************** -->
 
 <div class="doc_text">
@@ -123,7 +123,7 @@
 </div>
 
 <!-- *********************************************************************** -->
-<div class="doc_section"><a name="language">The Basic Language</a></div>
+<h2><a name="language">The Basic Language</a></h2>
 <!-- *********************************************************************** -->
 
 <div class="doc_text">
@@ -181,7 +181,7 @@
 </div>
 
 <!-- *********************************************************************** -->
-<div class="doc_section"><a name="lexer">The Lexer</a></div>
+<h2><a name="lexer">The Lexer</a></h2>
 <!-- *********************************************************************** -->
 
 <div class="doc_text">