Add DeviceConfig to allow specifying configuration parameters (#569)

* Add DeviceConfig handling

* Update post review

* Further update post latest review

* Update following latest review

* Update docstrings and docs

docs/source/design.rst

@@ -23,9 +23,12 @@ This will return you a list of device instances based on the discovery replies.
 If the device's host is already known, you can use to construct a device instance with
 :meth:`~kasa.SmartDevice.connect()`.
 
-When connecting a device with the :meth:`~kasa.SmartDevice.connect()` method, it is recommended to
-pass the device type as well as this allows the library to use the correct device class for the
-device without having to query the device.
+The :meth:`~kasa.SmartDevice.connect()` also enables support for connecting to new
+KASA SMART protocol and TAPO devices directly using the parameter :class:`~kasa.DeviceConfig`.
+Simply serialize the :attr:`~kasa.SmartDevice.config` property via :meth:`~kasa.DeviceConfig.to_dict()`
+and then deserialize it later with :func:`~kasa.DeviceConfig.from_dict()`
+and then pass it into :meth:`~kasa.SmartDevice.connect()`.
+
 
 .. _update_cycle:
 

docs/source/deviceconfig.rst

@@ -0,0 +1,18 @@
+DeviceConfig
+============
+
+.. contents:: Contents
+   :local:
+
+.. note::
+
+    Feel free to open a pull request to improve the documentation!
+
+
+API documentation
+*****************
+
+.. autoclass:: kasa.DeviceConfig
+    :members:
+    :inherited-members:
+    :undoc-members:

docs/source/index.rst

@@ -15,3 +15,4 @@
    smartdimmer
    smartstrip
    smartlightstrip
+   deviceconfig