Add ConfigReporter to generate .scss-lint.yml

Returns a YAML configuration where all linters are disabled which caused a lint. You can use this as a `.scss-lint.yml` file. The point is to remove these configuration records one by one while fixing the reported lints in the code.

I think it could be a starting point if you add `scss-lint` to an existing project. There is room for improvements (e.g. excluding single files or suggesting configuration options) but one step after the other. :)

Let me know what you think about this.