stylecow plugin nested-rules

Stylecow plugin to add support for nested rules.

More info:

• https://drublic.de/blog/the-css-hierarchies-module-level-3/
• http://lists.w3.org/Archives/Public/www-style/2011Jun/0022.html

You write:

body {
  & p {
    color: blue;
  }
  & > section {
    & h1,
    & h2 {
      color: red;

      &.green {
        color: green;
      }
    }
  }
  & div,
  & span {
    & a {
      color: orange;
    }
  }
}

And stylecow converts to:

body p {
  color: blue;
}
body > section h1,
body > section h2 {
  color: red;
}
body > section h1 .green,
body > section h2.green {
  color: green;
}
body div a,
body span a {
  color: orange;
}