Update docs with more howto examples (#968)

Co-authored-by: Teemu R. <tpr@iki.fi>

kasa/interfaces/lightpreset.py

@@ -1,4 +1,72 @@
-"""Module for LightPreset base class."""
+"""Interact with TPLink Light Presets.
+
+>>> from kasa import Discover, Module, LightState
+>>>
+>>> dev = await Discover.discover_single(
+>>>     "127.0.0.3",
+>>>     username="user@example.com",
+>>>     password="great_password"
+>>> )
+>>> await dev.update()
+>>> print(dev.alias)
+Living Room Bulb
+
+Light presets are accessed via the LightPreset module. To list available presets
+
+>>> light_preset = dev.modules[Module.LightPreset]
+>>> light_preset.preset_list
+['Not set', 'Light preset 1', 'Light preset 2', 'Light preset 3',\
+ 'Light preset 4', 'Light preset 5', 'Light preset 6', 'Light preset 7']
+
+To view the currently selected preset:
+
+>>> light_preset.preset
+Not set
+
+To view the actual light state for the presets:
+
+>>> len(light_preset.preset_states_list)
+7
+
+>>> light_preset.preset_states_list[0]
+LightState(light_on=None, brightness=50, hue=0,\
+ saturation=100, color_temp=2700, transition=None)
+
+To set a preset as active:
+
+>>> dev.modules[Module.Light].state  # This is only needed to show the example working
+LightState(light_on=True, brightness=100, hue=0,\
+ saturation=100, color_temp=2700, transition=None)
+>>> await light_preset.set_preset("Light preset 1")
+>>> await dev.update()
+>>> light_preset.preset
+Light preset 1
+>>> dev.modules[Module.Light].state  # This is only needed to show the example working
+LightState(light_on=True, brightness=50, hue=0,\
+ saturation=100, color_temp=2700, transition=None)
+
+You can save a new preset state if the device supports it:
+
+>>> if light_preset.has_save_preset:
+>>>     new_preset_state = LightState(light_on=True, brightness=75, hue=0,\
+ saturation=100, color_temp=2700, transition=None)
+>>>     await light_preset.save_preset("Light preset 1", new_preset_state)
+>>> await dev.update()
+>>> light_preset.preset  # Saving updates the preset state for the preset, it does not \
+set the preset
+Not set
+>>> light_preset.preset_states_list[0]
+LightState(light_on=None, brightness=75, hue=0,\
+ saturation=100, color_temp=2700, transition=None)
+
+If you manually set the light state to a preset state it will show that preset as \
+    active:
+
+>>> await dev.modules[Module.Light].set_brightness(75)
+>>> await dev.update()
+>>> light_preset.preset
+Light preset 1
+"""
 
 from __future__ import annotations