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
"""Documentation builder for Airflow."""
    def __init__(self, package_name: str):
        self.package_name = package_name
    @property
    def _doctree_dir(self) -> str:
        return f"{DOCS_DIR}/_doctrees/docs/{self.package_name}"
    @property
    def _out_dir(self) -> str:
        if self.package_name == 'apache-airflow-providers':
            
            
            return f"{DOCS_DIR}/_build/docs/{self.package_name}"
        else:
            return f"{DOCS_DIR}/_build/docs/{self.package_name}/latest"
    @property
    def _src_dir(self) -> str:
        return f"{DOCS_DIR}/{self.package_name}"
    def clean_files(self) -> None: