Add LocationMessage example to basic.py

[biemster]

It took me quite a bit of investigation how to send a location message, but it's actually quite easy:

def location_message(label,lat,lon) -> Message:
    message = Message(locationMessage=LocationMessage(name=label, degreesLatitude=lat, degreesLongitude=lon))
    return message

client.send_message(chat, location_message(label='label text', lat=46.2333, lon=6.05))

I can make a PR if you accept those, otherwise these lines are easy to copy in basic.py if you prefer. Thanks for this awesome project!