Expose all virtual files on _vfs

[benjamincanac]

Currently, I am using http://localhost:3000/_vfs/ a lot to understand what's happening when using Nuxt but it seems that only the .nuxt/* are exposed.

It would be really nice to expose all the virtual files with Nitro to better understand what's happening under the hood 😊

[pi0]

Thanks for the suggestion! Moved to #173