Provide helpful info for .unibeautifyrc.yaml file

[Glavin001]

See https://github.com/djabraham/vscode-yaml-validation

Use a technique similar to YAML validation/linting.

• [ ] Validate the YAML meets the JSON Schema specs (blocked by #7 )
• [ ] Detect when options have no supported beautifier
  • [ ] Recommend beautifier which supports new option

[stevenzeck]

https://github.com/adamvoss/vscode-yaml

[Glavin001]

Awesome, exactly!