docs: workflows navigation (#1563)

* documentation: workflow nav addition

* documentation: add index page for workflows folder

Author: aaronmarkham

doc/index.rst

@@ -53,15 +53,14 @@ Amazon SageMaker provides implementations of some common machine learning algori
 
 
 *************
-Orchestration
+Workflows
 *************
-Orchestrate your SageMaker training and inference jobs with Kubernetes and Airflow.
+Orchestrate your SageMaker training and inference workflows with Airflow and Kubernetes.
 
 .. toctree::
-    :maxdepth: 1
+    :maxdepth: 2
 
-    kubernetes/index
-    airflow/index
+    workflows/index
 
 
 *************************

doc/airflow/index.rst renamed to doc/workflows/airflow/index.rst

@@ -0,0 +1,11 @@
+##########
+Workflows
+##########
+
+The SageMaker Python SDK supports managed training and inference for a variety of machine learning frameworks:
+
+.. toctree::
+    :maxdepth: 2
+
+    airflow/index
+    kubernetes/index