Improved documentation for ASCIIText component usage.

[aighita]

The component uses position: absolute and width/height: 100%, which requires a parent container with explicit dimensions.
I've updated the usage documentation.

<div className="min-h-screen flex items-center justify-center px-6 pt-32 pb-64">
    <div className="flex flex-col items-center text-center max-w-4xl w-full">
        <div className="relative w-full h-[500px]"> -- HERE
            <ASCIIText
                text='404'
                enableWaves={true}
                asciiFontSize={10}
            />
        </div>
        <p className="text-xl text-gray-400 mb-8">Oops! The page you are looking for does not exist.</p>
        <a 
            href="/"
            className="self-center flex items-center gap-2 text-gray-300 transition-colors hover:text-white cursor-target mb-4"
        >
            <ArrowLeft className="h-5 w-5" />
            Back to Home
        </a>
    </div>
</div>