Make device initialisation easier by reducing required imports (#936)

Adds username and password arguments to discovery to remove the need to import Credentials.
Creates TypeAliases in Device for connection configuration classes and DeviceType.
Using the API with these changes will only require importing either Discover or Device
depending on whether using Discover.discover() or Device.connect() to 
initialize and interact with the API.

docs/source/guides.md

@@ -6,12 +6,14 @@ This page contains guides of how to perform common actions using the library.
 
 ```{eval-rst}
 .. automodule:: kasa.discover
+    :noindex:
 ```
 
 ## Connect without discovery
 
 ```{eval-rst}
 .. automodule:: kasa.deviceconfig
+    :noindex:
 ```
 
 ## Get Energy Consumption and Usage Statistics

docs/source/reference.md

@@ -1,10 +1,11 @@
 # API Reference
 
-```{currentmodule} kasa
-```
-
 ## Discover
 
+
+```{module} kasa.discover
+```
+
 ```{eval-rst}
 .. autoclass:: kasa.Discover
     :members:
@@ -12,8 +13,51 @@
 
 ## Device
 
+```{module} kasa.device
+```
+
 ```{eval-rst}
-.. autoclass:: kasa.Device
+.. autoclass:: Device
+    :members:
+    :undoc-members:
+```
+
+
+## Device Config
+
+```{module} kasa.credentials
+```
+
+```{eval-rst}
+.. autoclass:: Credentials
+    :members:
+    :undoc-members:
+```
+
+```{module} kasa.deviceconfig
+```
+
+```{eval-rst}
+.. autoclass:: DeviceConfig
+    :members:
+    :undoc-members:
+```
+
+
+```{eval-rst}
+.. autoclass:: kasa.DeviceFamily
+    :members:
+    :undoc-members:
+```
+
+```{eval-rst}
+.. autoclass:: kasa.DeviceConnection
+    :members:
+    :undoc-members:
+```
+
+```{eval-rst}
+.. autoclass:: kasa.DeviceEncryption
     :members:
     :undoc-members:
 ```