* Add "license" object to the data file JSON schema
* Add license to GNU and GNU social
As an example, based on the discussion in:
https://github.com/simple-icons/simple-icons/issues/1167
* Use `"additionalProperties": false` in JSON schema
... to detect properties in the data file that shouldn't be there.
For more info, see:
https://json-schema.org/understanding-json-schema/reference/object.html
* Update JSON scheme descriptions
* Switch from jsonlint2 to jsonschema
This gives is better support for advanced features of JSON schema.
A couple of clarifications:
- There does exist a jsonschema-cli package, but it is rather limited
and crucially doens't exit with a non-zero exit code if there is an
error. (it is also pretty old and not maintained), hence the custom
script.
- I renamed .jsonlintschema 1) for clarity (lint is no longer accurate)
and 2) the .json extension allows easy imorting in the script and 3)
it adds syntax highlighting.
- The script outputs the number of errors in the end because the output
gets pretty big pretty quickly, this way you can see it easily from
your CLI.
- We could customize how the errors are logged, but I feel that is
beyond this PR.
* Two minor changes
* Use `oneOf` to require URL for custom licenses
The updated configuration allows the `"license"` field to be either
1) a SPDX license, optional with a URL
2) a "custom" license with a required URL
Read more about the "oneOf" feature of jsonschema at:
https://json-schema.org/understanding-json-schema/reference/combining.html#oneof
* Include license field in Contributing Guidelines
