Smooth scrolling to contacts

Clicking on the Contacts link in the nav now starts a smooth scrolling rather than an abrupt movement. With the previous implementation the user easily lost context because all other links in the navigation bar bring to another page. This helps the user understand that he is still on the same page. Better context, better usability. Nice indeed.

Signed-off-by: Emanuele <feliziani.emanuele@gmail.com>
Add the Let's work together link to the mobile menu

Now, when the mobile menu is open, it also features the Let's work together link. In this way, the form page (which is arguably the most important) is a lot easier to reach.

Signed-off-by: Emanuele <feliziani.emanuele@gmail.com>