Documentation: fix code block and literal block highlighting ...

Use shell script highlighting where it is resonable, use console
highlighting for transcripts, and fix some of the few cases where the
syntax was broken, resulting in text not being rendered at all.

Signed-off-by: Roland Hieber <r.hieber@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Docs: add some info about the Olimex's Olinuxino related bootloader images ...

Signed-off-by: Juergen Borleis <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>