feat: text shadow support and adveture 4.18.0 bump

[zml2008]

today in "abby attempts to do web," text shadows

[MiniDigger]

generally looks good, I just noticed that holograms/text display entities don't have text shadow. in vanilla, only the default one isn't shown.
I think just removing the !important here in style.css should be enough?

#output-pre.mode-hologram span {
    text-shadow: none !important;
}

that way css inheritance can work as expected: the default shadow color is set on the <pre>, that selector disables the default one and the render hook can then set it on the span which will override it as expected.

edit: the same might apply to server list, but I have no good way to test the vanilla behavior rn