Add Helm Chart Release Guide (#16121)
Add Helm Chart Release Guide (#16121)

This commits adds "manual" instructions to release Helm Chart.

This will be automated by a script over coming days.
nathanielvarona/airflow,danielvdende/incubator-airflow,apache/airflow,cfei18/incubator-airflow,dhuang/incubator-airflow,danielvdende/incubator-airflow,cfei18/incubator-airflow,apache/airflow,cfei18/incubator-airflow,apache/airflow,cfei18/incubator-airflow,danielvdende/incubator-airflow,sekikn/incubator-airflow,lyft/incubator-airflow,nathanielvarona/airflow,nathanielvarona/airflow,cfei18/incubator-airflow,apache/airflow,lyft/incubator-airflow,Acehaidrey/incubator-airflow,mistercrunch/airflow,apache/incubator-airflow,apache/airflow,mistercrunch/airflow,apache/incubator-airflow,mistercrunch/airflow,dhuang/incubator-airflow,danielvdende/incubator-airflow,cfei18/incubator-airflow,Acehaidrey/incubator-airflow,Acehaidrey/incubator-airflow,dhuang/incubator-airflow,apache/airflow,danielvdende/incubator-airflow,mistercrunch/airflow,Acehaidrey/incubator-airflow,bolkedebruin/airflow,sekikn/incubator-airflow,lyft/incubator-airflow,nathanielvarona/airflow,apache/incubator-airflow,bolkedebruin/airflow,Acehaidrey/incubator-airflow,lyft/incubator-airflow,nathanielvarona/airflow,dhuang/incubator-airflow,Acehaidrey/incubator-airflow,danielvdende/incubator-airflow,sekikn/incubator-airflow,bolkedebruin/airflow,sekikn/incubator-airflow,apache/incubator-airflow,bolkedebruin/airflow,nathanielvarona/airflow,bolkedebruin/airflow