This schema is helpful for people writing custom target spec JSON. It
can provide autocomplete in the editor, and also serves as documentation
when there are documentation comments on the structs, as `schemars` will
put them in the schema.
- Document test intent to check for `-Whelp` suggestion if
`--print=lints` was specified.
- Move this test under `tests/ui/print-request/` and rename it to
`print-lints-help.rs` to better reflect what it is checking.