Added text and a new figure to show the resulting directory
structure from running the SDK installation .sh script.
(From yocto-docs rev: 3c5aec4a0088262e60ee6becb5e34552feeb6151)
Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>