Change Copy Prevention to Paste Prevention in Tutorial

[jillesme]

I've been loving Svelte and SvelteKit a lot. Sometimes when you Google a specific terms, you get redirected to the playground. For example, SvelteKit environment variables:

I understand we don't want people copy and pasting code, but not being able to copy for purposes other than the tutorial is frustrating. I presume the reason we don't want people to copy, is to prevent them from blindly copy and pasting code without learning.

What if instead we blocked pasting code? It would achieve the same effect: prevent people from copy/pasting code inside the tutorial editor, but for the rest of us that stumble on a tutorial page and use it as reference, we can copy without the annoying pop-up.

[Conduitry]

Duplicate of #1216.