Add set_repeat_days to SmartTask

[blast-hardcheese]

• Added Days with constants into const.py
• Added TaskControl.set_repeat_days for SmartTask
• Added lights to the onboarding helper text
• Added sockets and socket to __main__
• Added an example text for how to use set_repeat_days in __main__

[blast-hardcheese]

In response to "We don't use the const module above. I think we should be consistent",

I think having symbolic names for the individual days is critical as a disambiguation, since "0b1000000 is Monday" isn't obvious, and avoiding trial and error seems wise

[blast-hardcheese]

Actually, I didn't see WEEKDAYS initially. If there's some other way you'd like me to approach this, I'm happy to do so

[blast-hardcheese]

This would avoid the modification to const.py:

Suggested change

	print("> from pytradfri.const.Days import TUESDAY, THURSDAY, SATURDAY, SUNDAY")
	print("> days = TUESDAY | THURSDAY | SATURDAY | SUNDAY")
	print("> api(socket.socket_control.set_repeat_days(days))")
	print("> from pytradfri.smart_task import WEEKDAYS")
	print("> days = WEEKDAYS.tue | WEEKDAYS.thur | WEEKDAYS.sat | WEEKDAYS.sun")
	print("> api(socket.socket_control.set_repeat_days(days))")

[MartinHjelmare]

Please use the existing constant in smart_task.