Text encoding breaks yaml validation

Encountered interesting issue via copying spec's out of the documentation and trying to run it. This worked fine, until the downloaded specification was edited to add some new keys, a depends key, which resulted in immediate yaml validation errors about that being an invalid key. The only recourse was manually retyping the whole specification. That, combined with throwing a 'not-ascii' regex at the buffer that marked nearly every character suggests a text encoding issue? More investigation required to ensure examples can actually be taken from the documentation directly.

Initial testing/issue discovered on MacOS.

Start by reproducing the issue with a specification copied from the documentation, then edit it to add a depends key and run YAML validation on macOS. Trace the validation entry point and inspect how text is decoded before the key check and not-ascii regex run. Done means copied documentation examples remain valid after editing and non-ASCII text is handled correctly.