Update README, Cookbook and documentation

[PythooonUser]

Summary

Since we are about to introduce many name regarding changes, we need to update the documentation accordingly.

The work needed to be done here is to:

• Change the examples in the README
• Change the examples in the setup.py PyPi file
• Change the examples in the GitHub Cookbook
• Change the internal docstrings
• Change what is left in the Sphinx documentation

[PythooonUser]

This is of course an issue to tackle after all the work is done!

[senpos]

Change the examples in the README

What about echo_bot example using the new on_event decorator?

from twitchobserver import Observer, ChatEventType

observer = Observer(<BOT_USERNAME>, <BOT_OAUTH>)
observer.join_channel(<CHANNEL>)


@observer.on_event(ChatEventType.TWITCHCHATMESSAGE)
def echo_handler(event):
    observer.send_message(event.message, event.channel)

observer.start()

on_command bot would be also cool to have there, once the feature appear

I will try to handle all of this at the evening, once naming issue will be discussed

[PythooonUser]

I think we should definetly show both ways, decorators being only quality of life improvements.

[joshuaskelly]

I think the Cookbook should have actual use cases that folks can directly use. We also should have one that uses decorators. 😄