Provide Config Schema

[Nerixyz]

RedHat's YAML language server provides the option to associate a file with some schema by adding a special top level comment (or through the settings). It would be really helpful is MrDocs would provide a schema for the config. This makes editing a much nicer experience, in my opinion. Mkdocs-material provides such a schema for example.

Given that MrDocs has the configuration in a machine-readable format already, this seems easy to add. I modified generate-config-info.py a bit to generate a JSON (and thus YAML) schema:

If this something you'd like to add? If so, I'd open a PR.

[vinniefalco]

Very good idea! This would be nicer as a pull request though ;)