Add tut-web to sidebar

SIDEBAR.ftl.md

 ### Tutorials
 
 * [Designing and Implementing RESTful Web Services with Spring][tut-rest]
+* [Designing and Implementing a Web Site with Spring][tut-web]
 
 [tut-rest]: /guides/tutorials/rest
+[tut-web]: /guides/tutorials/web
 
 ### Concepts and technologies
 

SIDEBAR.md

 ### Tutorials
 
 * [Designing and Implementing RESTful Web Services with Spring][tut-rest]
+* [Designing and Implementing a Web Site with Spring][tut-web]
 
 [tut-rest]: /guides/tutorials/rest
+[tut-web]: /guides/tutorials/web
 
 ### Concepts and technologies