It's undocumented whether tippies should be destroyed when no longer needed

[x-yuri]

Bug description

Let's say you added a tippy to an element, but then you destroyed the latter (e.g. el.parentNode.innerHTML = ''). Should the tippy be destroyed manually as well (el._tippy.destroy())? If so, I think it's important to mention it in the docs since I'd expect that many will not do any clean up. If it isn't so, I think it's also important to mention it to appease the paranoid types :)