Update the Application Development Primer to describe the new menuconfig
configuration interface:
- Update the section explaining how the configuration is navigated,
changed, and saved
- Add a section explaining how to jump directly to a symbol in the
configuration interface
- Replace mconf screenshots with menuconfig.py screenshots. Remove some
screenshots that are no longer used.
- Remove the section explaining how to load arbitrary .config files
from within the configuration interface. That feature hasn't been
implemented yet in menuconfig.py.
- Do various minor language cleanup
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>