Docs playground uses incompatible version of Noir

[TomAFrench]

The Noir playground in the docs is using an old version of Noir compared to what we're releasing. As there's been a number of breaking changes, users cannot take noir code from the playground and have it work with nargo and vice versa.

We should update this to be current so that code is portable between the two.

[signorecello]

Thanks for flagging!

I'll update the playground for 0.22.0 and update it here.

@Thunkar is also updating it to use the new source resolver, and a design request was submitted to make it look better