Online demo not parsing example wit file

[joepio]

The demo at https://bytecodealliance.github.io/wit-bindgen/ shows this without editing anything:

expected '.', found keyword `default`
     --> input:8:3
      |
    8 |   default export interface {
      |   ^

It has to do with the default .wit file, which does not currently parse. This could be a parsing bug. Anyways, I think it would be better to use a .wit example that is guaranteed to work, e.g. something that's synced with the examplre

[joepio]

Since the online demo might be removed soon, perhaps looking into this issue isn't worth it.

[alexcrichton]

Yes this is getting removed in #463 so I'm going to close this, but thanks for the report though!