feat(js-api): add types for Editor Config Contributor client extension

[markocikos]

References

• LPS-187309 Apply editor config contributor client extensions to CKEditor
• Related to https://github.com/liferay-frontend/liferay-portal/pull/3902

What is the goal of this PR?

Adding public types for Editor Config Contributor client extension.

Notes:

• I intentionally named this in a generic way, EditorConfigTransformer and not EditorConfigContributor. We plan to add a different CET in the future, that will not use the Java EditorConfigContributor framework in DXP. That CET will still be able to use this API, as both will do the same config transformation in the end.
• I don't think we want to manage anything more specific than [key: string]: any; for config structure. This is based on the third-party APIs and is likely to change with time. Being so generic will also enable us to be consistent with APIs for CKEditor 5 or other editors. I added in commited docs link to offical docs for the config object.

[markocikos]

@izaera I force pushed changes, please take a look. In addition, do you know what causes the Pull Request Labeler / triage check failure? The error is quite cryptic to me, found unexpected type for label '10.x' (should be array of config options)

[izaera]

do you know what causes the Pull Request Labeler / triage check failure?

Looks like an internal issue in GH actions. I'd rerun it again.

[izaera]

LGTM!

[markocikos]

@izaera Can you release new version of @liferay/js-api? I can try, but I'm not sure if I have permissions, or if there are and hidden quirks of this repo.

[izaera]

let me check :+1:

[izaera]

It's as explained here -> https://github.com/liferay/liferay-frontend-projects/blob/master/projects/js-toolkit/CONTRIBUTING.md

I'll try it now bc it's been long since I don't release a version of this project, but IIRC there's nothing special with this project. Only that we are releasing pre-versions until we decide to make it effective and start to maintain proper versioning of the contracts.

[izaera]

There you go -> https://github.com/liferay/liferay-frontend-projects/releases/tag/js-api%2Fv0.6.0-pre.0

Next time you simply need to run the steps described in CONTRIBUTING.md.

As for the permissions, you should be fine because we set all our npm packages to the same user group (liferay devs), so you should have permissions too.