docs: Add new Athena URI scheme awsathena+rest://

See also some discussions on laughingman7743/PyAthenaJDBC#62

docs/installation.rst

@@ -314,6 +314,8 @@ Here's a list of some of the recommended packages.
 +---------------+-------------------------------------+-------------------------------------------------+
 |  Athena       | ``pip install "PyAthenaJDBC>1.0.9"``| ``awsathena+jdbc://``                           |
 +---------------+-------------------------------------+-------------------------------------------------+
+|  Athena       | ``pip install "PyAthena>1.2.0"``    | ``awsathena+rest://``                           |
++---------------+-------------------------------------+-------------------------------------------------+
 |  Vertica      | ``pip install                       |  ``vertica+vertica_python://``                  |
 |               | sqlalchemy-vertica-python``         |                                                 |
 +---------------+-------------------------------------+-------------------------------------------------+
@@ -341,6 +343,11 @@ Where you need to escape/encode at least the s3_staging_dir, i.e., ::
 
     s3://... -> s3%3A//...
 
+You can also use `PyAthena` library
+
+    awsathena+rest://{aws_access_key_id}:{aws_secret_access_key}@athena.{region_name}.amazonaws.com/{schema_name}?s3_staging_dir={s3_staging_dir}&...
+
+_(See more details at https://github.com/laughingman7743/PyAthena#sqlalchemy.)_
 
 Caching
 -------
@@ -362,7 +369,7 @@ For setting your timeouts, this is done in the Superset metadata and goes
 up the "timeout searchpath", from your slice configuration, to your
 data source's configuration, to your database's and ultimately falls back
 into your global default defined in ``CACHE_CONFIG``.
-	
+
 .. code-block:: python
 
     CACHE_CONFIG = {
@@ -657,13 +664,13 @@ Note that it's also possible to implement you own logger by deriving
 Install Superset with helm in Kubernetes
 --------------
 
-You can install Superset into Kubernetes with Helm <https://helm.sh/>. The chart is 
+You can install Superset into Kubernetes with Helm <https://helm.sh/>. The chart is
 located in ``install/helm``.
 
 To install Superset into your Kubernetes:
 
 .. code-block:: bash
 
-    helm upgrade --install superset ./install/helm/superset 
+    helm upgrade --install superset ./install/helm/superset
 
 Note that the above command will install Superset into ``default`` namespace of your Kubernetes cluster.