docs(quickstart): fix broken link to tutorial (#2278)

Author: chalin

public/docs/ts/latest/quickstart.jade

@@ -215,7 +215,7 @@ block install-packages
     application, you'd likely import [`FormsModule`](../latest/api/forms/index/FormsModule-class
     .html) as well as [`RouterModule`](../latest/api/router/index/RouterModule-class.html) and
     [`HttpModule`](../latest/api/http/index/HttpModule-class.html). These are introduced in the
-    [Tour of Heroes Tutorial](../tutorial/).
+    [Tour of Heroes Tutorial](./tutorial/).
 
 
 .l-main-section