On env-read-docs, do callbacks

def call_env_before_read_docs(cls, kb_app, sphinx_app: Sphinx,
                                  sphinx_env: BuildEnvironment,
                                  docnames: List[str]):
        """ On env-read-docs, do callbacks"""

        for callback in EventAction.get_callbacks(kb_app,
                                                  SphinxEvent.EBRD):
            callback(kb_app, sphinx_app, sphinx_env, docnames)