Johannes Doberer

Add wc client api docu

1

Currently we don't have a webcomponent client api documentation like https://docs.luigi-project.io/docs/luigi-client-api tbd

When a user access our [docu page](https://docs.luigi-project.io/docs/getting-started) we don't mention anything about Luigi(Compound)Container. We should change this... tbd....

Possibility to hide the x button in a modal in the top right corner

generate custom-element.json of LuigiContainer and LuigiCompoundContainer

Blocked by now. We have no `client-support-ui5` tag and I would test it when it comes to a new release.

#3631 #3862