Documentation: use https for Pengutronix services ...

Also adapt the links to git.pengutronix.de to use the cgit URLs instead the
old gitweb ones.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

docs: correct link to microcom repo ...

It's not nice to land on a 404 page and having to
search for the right location manually.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

doc: make "System setup" an appendix ...

Note that I used "Appendix: " as text, because it looks like
python-sphinx doesn't know about appendices.

Signed-off-by: Holger Schurig <holgerschurig@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Documentation: Add new sphinxs docs ...

This is a rewrite of the Documentation in reStructuredText format using
Sphinx as build system, see http://sphinx-doc.org/.

The documentation is built into static html pages with 'make docs'.
The pages can be found under Documentation/html after building.

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