Update the rules channel

[rafaelalmeidatk]

I removed the old text that was mostly referencing the Next.js Conf and added some rules specific for the server. I included back the commented messages that would be from the other bot. Imo we can delete these messages because it's kinda inconvenient having them there without us being able to edit them all in the same bot.

Since we implemented the custom roles with the new Onboarding Questions, I removed them from the welcome message