The documentation does not mention usage of single configuration files

While this is a neat feature added in !36 (merged) and !65 (merged) but the documentation barely advertises it and nobody knows about it.

@andre.anjos since you added this feature, do you also want to document it?

This feature was also improved here !65 (merged) by @mguenther

I'm out of time, currently. Sorry.

created branch 78-the-documentation-does-not-mention-usage-of-single-configuration-files

mentioned in merge request !92 (merged)

closed via commit e1659aed

mentioned in commit e1659aed