manual: misc. post-{build, image} scripts fixes

* update post-build scripts mechanism that now support several scripts
* fix formatting

Signed-off-by: Samuel Martin <s.martin49@gmail.com>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
1 file changed