update docs for unsupported Windows features

docsite/rst/playbooks_async.rst

@@ -79,6 +79,9 @@ following::
    "check on it later" task to fail because the temporary status file that
    the ``async_status:`` is looking for will not have been written or no longer exist 
 
+.. note::
+   ``async:`` is not currently supported for Windows targets
+
 .. seealso::
 
    :doc:`playbooks`

docsite/rst/playbooks_environment.rst

@@ -56,6 +56,9 @@ to define an environment hash might be a group_vars file, like so::
       http_proxy: http://proxy.bos.example.com:8080
       https_proxy: http://proxy.bos.example.com:8080
 
+.. note::
+   ``environment:`` is not currently supported for Windows targets
+
 .. seealso::
 
    :doc:`playbooks`