Extra links supported for operators coming from third-party packages:

airflow.serialization.serialized_objects.BUILTIN_OPERATOR_EXTRA_LINKS

tests/core/test_providers_manager.py
'apache-airflow-providers-slack',
    'apache-airflow-providers-snowflake',
    'apache-airflow-providers-sqlite',
    'apache-airflow-providers-ssh',
    'apache-airflow-providers-telegram',
    'apache-airflow-providers-vertica',
    'apache-airflow-providers-yandex',
    'apache-airflow-providers-zendesk',
]
CONNECTIONS_LIST = [
    'azure_batch',
    'azure_cosmos',
    'azure_data_lake',
    'cassandra',
    'cloudant',
    'dataprep',
    'docker',
    'elasticsearch',
    'exasol',
    'gcpcloudsql',
    'gcpssh',
    'google_cloud_platform',
    'grpc',
    'hive_cli',
    'hiveserver2',
    'imap',
    'jdbc',
    'jira',
    'kubernetes',
    'mongo',