Add information regarding the CuBox-i

Signed-off-by: Carlos Rafael Giani <dv@pseudoterminal.org>
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
First User Guide Commit

Include the list of topics to be included in the guide, with only
the 'Building and Boot in N-steps' document populated. We will
start populating the rest and include other topics if necessary.

Signed-off-by: Leonardo Sandoval <leo@freescale.com>
Brief description of commonly used folders

Signed-off-by: Leonardo Sandoval <leo@freescale.com>
Brief description of Yocto Metadata

Signed-off-by: Leonardo Sandoval <leo@freescale.com>
Some commonly development tasks

These are the ones included on the commit:
    * Creating a new Layer
    * Patching and Compiling the Kernel
    * Contributing to the Yocto Project

Signed-off-by: Leonardo Sandoval <leo@freescale.com>