How to mark the official standard?

[ffes]

In https://github.com/editorconfig/editorconfig/issues/298 we discussed that we need a way to specify the official standard configuration.

For example the YAML specs require spaces for indention and Makefile need tab indention

[deinok]

One flavour and only one can have an attribute named default with a true. The default value of a flavour of the attribute "default" is false