"Services" link to "guidelines"

In navigation bar, there was the link to "Services". So far it only contains the guidelines.

One could either

1. include Cloud and Consulting stuff to that page (but it would be redundant with the big buttons on main page); or
2. make it more specific and name it "Guidelines" 2.1. all older links to /services are being redirected. 2.2. more guidelines from best-practices could be added there

Here is variant 2. @frust45 @SpickerHZB what do you think?

closes #80 (closed)