Update Databricks workflows in Airflow features comparison against Da…

…tabricks UI features (#81)

It appears that Databricks UI now supports retrying/repairing a single task from the UI.

Additionally, they also have rolled out now source control for workflows. https://docs.databricks.com/en/workflows/jobs/how-to/use-repos.html

This PR updates our documentation to update the same.

closes: astronomer/issues-airflow#773

README.md

@@ -13,9 +13,9 @@ There are a few advantages to defining your Databricks Workflows in Airflow:
 | Authoring interface                  | _Web-based via Databricks UI_ | _Code via Airflow DAG_ |
 | Workflow compute pricing             |              ✅               |           ✅           |
 | Notebook code in source control      |              ✅               |           ✅           |
-| Workflow structure in source control |                               |           ✅           |
+| Workflow structure in source control |              ✅               |           ✅           |
 | Retry from beginning                 |              ✅               |           ✅           |
-| Retry single task                    |                               |           ✅           |
+| Retry single task                    |              ✅               |           ✅           |
 | Task groups within Workflows         |                               |           ✅           |
 | Trigger workflows from other DAGs    |                               |           ✅           |
 | Workflow-level parameters            |                               |           ✅           |