Media queries support

[ortizvinicius]

Currently there is no media queries support, you need to add a text, like this:

$cshp->text("@media screen and (min-width: 768px) {")
$cshp->rule(...)
$cshp->text("}")

In next version will look something like this:
$cshp->rule("a", ["td:n"], ["screen", "768px"]);