vdk-airflow: populate readme (#924)

Author: antoniivanov

projects/vdk-plugins/airflow-provider-vdk/README.md

@@ -1,3 +1,62 @@
-## Versatile Data Kit Airflow provider
+# Versatile Data Kit Airflow provider
 
 A set of Airflow operators, sensors and a connection hook intended to help schedule Versatile Data Kit jobs using Apache Airflow.
+
+# Usage
+
+To install it simply run:
+```
+pip install airflow-provider-vdk
+```
+
+Then you can create a workflow of data jobs (deployed by VDK Control Service) like this:
+
+```
+from datetime import datetime
+
+from airflow import DAG
+from vdk_provider.operators.vdk import VDKOperator
+
+with DAG(
+    "airflow_example_vdk",
+    schedule_interval=None,
+    start_date=datetime(2022, 1, 1),
+    catchup=False,
+    tags=["example", "vdk"],
+) as dag:
+    trino_job1 = VDKOperator(
+        conn_id="vdk-default",
+        job_name="airflow-trino-job1",
+        team_name="taurus",
+        task_id="trino-job1",
+    )
+
+    trino_job2 = VDKOperator(
+        conn_id="vdk-default",
+        job_name="airflow-trino-job2",
+        team_name="taurus",
+        task_id="trino-job2",
+    )
+
+    transform_job = VDKOperator(
+        conn_id="vdk-default",
+        job_name="airflow-transform-job",
+        team_name="taurus",
+        task_id="transform-job",
+    )
+
+    [trino_job1, trino_job2] >> transform_job
+
+```
+
+# Example
+
+See [full example here](https://github.com/vmware/versatile-data-kit/tree/main/examples/airflow-example)
+
+# Demo
+
+You can see demo during one of the community meetings here: https://www.youtube.com/watch?v=c3j1aOALjVU&t=690s
+
+# Architecture
+
+See the [vdk enhancement proposal spec here](https://github.com/vmware/versatile-data-kit/tree/main/specs/vep-554-apache-airflow-integration)