Include OpenAPI specification
One standard way to share what are the capabilities of an API is by writing an OpenAPI specification. This one can be easily shared and displayed using a visualizer like Swagger UI which is also included in GitLab like here: Autosubmit API v4.0.0b3 OpenAPI. Also, it can be shown when using ReadTheDocs.
So, this can potentially replace the documentation we have on the wiki and have a unique source about the API description.