Update new_user top page redirect reason

The goal of this text is to sublty hint that reading is the way to graduate out of it.

As suggested in https://meta.discourse.org/t/new-visitor-message-confusing-people/12508/12?u=riking

![image](https://f.cloud.github.com/assets/627891/2105394/af8e2740-8f8b-11e3-8d67-5f20c8c2125e.png)