Hi.

I have fantastic news. We are growing! 🐈 Together with this, our documentation grows and we have newer needs and requirements. 

We currently only publish documentation for our app releases. 
 - https://airflow.apache.org/docs/stable/

But our community is also working on other products that have a different release cycle, use case, docs build tool and needs
- Production Docker image: https://hub.docker.com/r/apache/airflow
- REST API: https://airflow.readthedocs.io/en/latest/stable-rest-api-ref.html (it has a separate version number, so a version index could be helpful. We can also set the version to the application version)
- Backport/provider packages: https://github.com/apache/airflow/tree/master/backport_packages
- Helm Chart: https://github.com/apache/airflow/tree/master/chart
- [API Clients for Apache Airflow](https://github.com/apache/airflow/issues/10176)
  - Go: https://github.com/apache/airflow-client-go 
  - Python: https://github.com/apache/airflow-client-python
  - Java: https://github.com/apache/airflow-client-java
  - Javascript: https://github.com/apache/airflow-client-javascript
- Apache Airflow on K8S Operator: https://github.com/apache/airflow-on-k8s-operator

and other: https://github.com/apache/airflow/issues/10550, https://github.com/apache/airflow/issues/10552

I think it is worth considering how we want to inform users about these products on our website.  

One solution is to create an index at: `https://airflow.apache.org/docs/` (currently there is a redirection to the latest stable version of the documentation), which will refer you to separate documentation for each product.
It will look similar to the examples:
https://mc-stan.org/
https://cloud.google.com/sql/docs/
https://www.terraform.io/docs/

An alternative solution is moving all documentations to our app documentation:
https://github.com/apache/airflow/pull/11136
https://github.com/apache/airflow/pull/10998

What is our plan for this documentation? Do we need to standardize our documentation building tools? What requirements does each documentation have, e.g. do we always need versioning? 
CC: @kaxil @potiuk 

docs/build_docs.py
print(f" - {pkg}")
    docs_only = args.docs_only
    spellcheck_only = args.spellcheck_only
    disable_checks = args.disable_checks
    package_filters = args.package_filter
    print("Current package filters: ", package_filters)
    current_packages = (
        [p for p in available_packages if any(fnmatch.fnmatch(p, f) for f in package_filters)]
        if package_filters
        else available_packages
    )
    with with_group(f"Documentation will be built for {len(current_packages)} package(s)"):
        for pkg in current_packages:
            print(f" - {pkg}")
    all_build_errors: Dict[Optional[str], List[DocBuildError]] = {}
    all_spelling_errors: Dict[Optional[str], List[SpellingError]] = {}
    package_build_errors, package_spelling_errors = build_docs_for_packages(
        current_packages=current_packages,
        docs_only=docs_only,
        spellcheck_only=spellcheck_only,
    )
    if package_build_errors:
        all_build_errors.update(package_build_errors)
    if package_spelling_errors:
        all_spelling_errors.update(package_spelling_errors)
    to_retry_packages = [
        package_name
        for package_name, errors in package_build_errors.items()
        if any(any((m in e.message) for m in ERRORS_ELIGIBLE_TO_REBUILD) for e in errors)
    ]