Request - add support to Style for list styling

[reubenfirmin]

Please add support for:

• list-style
• counter-reset
• counter-increment
• the counter() css function

[rjaros]

Remember you can always use setStyle(), like this:

val olStyle = Style("ol") {
    setStyle("counter-reset", "section")
    setStyle("list-style-type", "none")
}

val liStyle = Style("li", pElement = PElement.BEFORE) {
    setStyle("counter-increment", "section")
    setStyle("content", "counters(section, \".\") \" \"")
}

[rjaros]

I've implemented type-safe listStyle property, but counter and content css properties are just strings, so in my opinion it's better to just use setStyle.