Add Getting Started page and information for the CAN-Bus interface
This feature extends the information of the i.MX8MM with information on the CAN-Bus interface and adds short getting started page for the i.MX8MM boards, so the users who bought Demo Kits can see what and how they should hook up the board. Small spellings corrections and also added a line to the index file to make the getting started page visible to the user more quickly.