feat: Add terminal()->clear() method.

[xiCO2k]

This PR adds a function to allow the terminal to be cleared.

Example:

use function Termwind\{render, terminal};

terminal()->clear();

render(<<<'HTML'
    <div class="my-2 mx-2 w-full bg-green-500 font-bold text-black text-center">
        Now there is a capability to clear the "messy" terminal screen
    </div>
HTML);

Before:

After:

[nunomaduro]

Can you document this, and all terminal features in this PR?

[xiCO2k]

done ;)