Document test() method in reference

[memsharded]

It seems the docs for this method is not there: https://docs.conan.io/en/latest/reference/conanfile.html

[uilianries]

Related issue: https://github.com/conan-io/conan/issues/6448

[atrelinski]

Is there a chance to document the test() method?
I love your documentation and used it a thousand times, but for the test(), I needed some specifics and couldn't find them.
I see this task is open for quite a long time.

[memsharded]

Lets at least add the basics: #2164 (this method is very simple, probably doesn't require more. But what would be necessary is better docs about enviroment and executing things, TBD with the new conan.tools.env features)