Pest parser grammar for Workflow Description Language (WDL).
```wdl use pest::iterators::Pair; use pestwdl1 as wdl;
fn main() { let text = r#" version 1.0
workflow foo {
}
"#;
let root: Pair<'_, wdl::Rule> =
wdl::parse_document(text).expect("Error parsing WDL document");
...
}