These files were previously stored in the CI source tree, but they do
belong here. They describe the different configurations under which we
want to build Qt and its submodules, in terms of underlying virtual
machine template, host OS, target OS and CI related features that may
also map to Qt configuration features.

Task-number: QTQAINFRA-1074
Change-Id: I7ce48e3b15da757166eeac7531478d3746c8aa7f
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@qt.io>