Improved welcome page.

The feature set of the new page:

 - HTML5 compliant;
 - Description of why the user is seeing the page and what his next
   step should be;
 - Links to official community and commercial support websites.
diff --git a/docs/html/index.html b/docs/html/index.html
index 1f79275..2ca3b95 100644
--- a/docs/html/index.html
+++ b/docs/html/index.html
@@ -1,8 +1,25 @@
+<!DOCTYPE html>
 <html>
 <head>
 <title>Welcome to nginx!</title>
+<style>
+    body {
+        width: 35em;
+        margin: 0 auto;
+        font-family: Tahoma, Verdana, Arial, sans-serif;
+    }
+</style>
 </head>
-<body bgcolor="white" text="black">
-<center><h1>Welcome to nginx!</h1></center>
+<body>
+<h1>Welcome to nginx!</h1>
+<p>If you see this page, the nginx web server is successfully installed and
+working. Further configuration is required.</p>
+
+<p>For online documentation and support please refer to
+<a href="http://nginx.org/">nginx.org</a>.<br/>
+Commercial support is available at
+<a href="http://nginx.com/">nginx.com</a>.</p>
+
+<p><em>Thank you for using nginx.</em></p>
 </body>
 </html>