Updates based on discussion and changes in supported features.
- Make the guide shorter by removing content that's not relevant to
most users who are truly just getting started, such as information
about pre-LTS versions that did not support west, and by being more
concise in some places.
- Decrease the number of colored boxes. At the latest TSC F2F, the
"note / warning / note / tip" contents were identified as a
readability problem.
- Add additional information based on new west features, like "west
boards".
Signed-off-by: Marti Bolivar <marti.bolivar@nordicsemi.no>
Marti Bolivar