Document sql_task configuration block in databricks_job resource (#1589)

Author: alexott

docs/resources/job.md

@@ -187,6 +187,16 @@ You can invoke Spark submit tasks only on new clusters. **In the `new_cluster` s
 
 You also need to include a `git_source` block to configure the repository that contains the dbt project.
 
+### sql_task Configuration Block
+
+One of the `query`, `dashboard` or `alert` needs to be provided.
+
+* `warehouse_id` - (Required) ID of the (the [databricks_sql_endpoint](sql_endpoint.md)) that will be used to execute the task.  Only serverless warehouses are supported right now.
+* `parameters` - (Optional) (Map) parameters to be used for each run of this task. The SQL alert task does not support custom parameters.
+* `query` - (Optional) block consisting of single string field: `query_id` - identifier of the Databricks SQL Query ([databricks_sql_query](sql_query.md)).
+* `dashboard` - (Optional) block consisting of single string field: `dashboard_id` - identifier of the Databricks SQL Dashboard [databricks_sql_dashboard](sql_dashboard.md).
+* `alert` - (Optional) block consisting of single string field: `alert_id` - identifier of the Databricks SQL Alert.
+
 ### email_notifications Configuration Block
 
 * `on_failure` - (Optional) (List) list of emails to notify on failure