* Describe what KIWI needs to run, further requirements, and for development
* Introduce 'ghkiwi' as prefix in "extlinks" to shorten external links and
to make linking to KIWI's GitHub repository more intuitive and consistent.
For example, the string :ghkiwi:`tox.ini` is replaced with
https://github.com/SUSE/kiwi/blob/master/tox.ini