Add JSON Schema of the config files to schemastore.org for autocompletion in editors

To improve the developer experience it would be really good if the config files were defined as JSON schema:s. I don't know maybe they already are that but then we only need to upload them to schemastore.org.

So VSCode and a bunch of editors could autocomplete the config files even though they are yaml files.

https://code.visualstudio.com/docs/languages/json#_json-schemas-and-settings
https://www.schemastore.org/json/