Name all subsystem reference consistently with an '_api' postfix and
clean up naming and folder structure in some cases.
Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
Moving all thread docs into 1 page was a bit too much. Split the section
a bit and remove redundant and useless sections and move some thread
related documentation from the scheduling page to threads (thread states
and priorities).
Add a new figure for thread states.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Move guides and APIs into separate directories and cleanup naming
introducing index files rather than named section files.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>