Valentin Anger

Having poked around in the `StdFileResource` read implementation could this possibly be related to [this Tokio issue](https://github.com/tokio-rs/tokio/issues/2466) about blocking reads blocking the runtime shutdown?

> When looking at the current code, I see that support has been added specifically for grammars conforming to JSON which are then translated into the corresponding GGBNF, and although...

@BruceMacD Apologies for the unsolicited ping, especially this close to the holidays. Doubly so if you're not the right person to ping for this, I based it on recent merges....

Given the recent release of tool support I have basically no need for this feature anymore. So I'll close this PR in favor of one of the many follow up...