playground: console formatting isn't applied

[Rich-Harris]

Describe the bug

also, the colours look terrible in dark mode

Reproduction

click the button

[trueadm]

Is there a format library that handles this already? I'm happy to work on this but would rather not reinvent the wheel.

[Rich-Harris]

Probably but I couldn't find anything with a quick keyword search on npm. The spec seems pretty simple though https://console.spec.whatwg.org/#formatter