RN: Add freescale_release_name variable

Signed-off-by: Daiane Angolini <daiane.angolini@freescale.com>
RN: Replace FSL Community BSP by variable

The variable project_name is used to represent the
project name, and should be used instead of the full
project name.

Signed-off-by: Daiane Angolini <daiane.angolini@freescale.com>
README: Add installation guide for sphinx extension

If you need additional help to blockdiag extension:

http://blockdiag.com/en/blockdiag/sphinxcontrib.html#install

Signed-off-by: Daiane Angolini <daiane.angolini@freescale.com>
RN: Install blockdiag extension

Signed-off-by: Daiane Angolini <daiane.angolini@freescale.com>
RN: Extend the introduction section

Add
 -What is FSL community BSP
 -What project is not
 -Motivation
 -What to expect
 -Main branch names
 -Upstreaming cycle
 -Differences between this project and Freescale official release

The comparative table is not included on purpose, as it is
going to be included in next commit.

Signed-off-by: Daiane Angolini <daiane.angolini@freescale.com>
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
RN: Add cross reference for Supported Boards section

Signed-off-by: Daiane Angolini <daiane.angolini@freescale.com>
RN: Add comparative table

The table is included in text section and compares the
two different releases: Freescale official release, and
community release.

Signed-off-by: Daiane Angolini <daiane.angolini@freescale.com>
RN: Add the product SoC family description section

This section should describe the different product
families covered.

Signed-off-by: Daiane Angolini <daiane.angolini@freescale.com>