Added mailinglist subscription form

I just added a mailinglist subscription box to this page, so you can subscribe to the Carendt.com mailinglist. I did this because I want to ask you, the visitors of this wonderful website, some questions about the site, and possibly send you some newsletters in the future. I hope you will help me make this website even better! The form is at the bottom of this page. Thanks in advance! 🙂