docs: use "Level 1" HTML5 features

Since we're using an HTML doctype we might as well use "Level 1" HTML5 features.
See more: http://mathiasbynens.be/notes/html5-levels#level-1

Fixes #2386.

doc/template.html

@@ -1,7 +1,7 @@
-<!DOCTYPE html>
-<html>
+<!doctype html>
+<html lang="en">
 <head>
-  <meta charset="UTF-8">
+  <meta charset="utf-8">
   <title>{{section}}Node.js v0.6.6 Manual &amp; Documentation</title>
   <link rel="stylesheet" href="assets/style.css">
   <link rel="stylesheet" href="assets/sh.css">
@@ -21,16 +21,16 @@
   <script src="assets/sh_main.js"></script>
   <script src="assets/sh_javascript.min.js"></script>
   <script>highlight(undefined, undefined, 'pre');</script>
-  <script type="text/javascript">
+  <script>
     var gaJsHost = (("https:" == document.location.protocol) ?
     "https://ssl." : "http://www.");
     document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E"));
   </script>
-  <script type="text/javascript">
+  <script>
     try {
       var pageTracker = _gat._getTracker("UA-10874194-2");
       pageTracker._trackPageview();
       } catch(err) {}</script>
-  <script type="text/javascript">highlight(undefined, undefined, 'pre');</script>
+  <script>highlight(undefined, undefined, 'pre');</script>
 </body>
 </html>