Allow server owners to control notifications of specific channels for the members of the server.

As of now, individuals can only change their own notification settings for any given server. Server owners should be allowed to mute their own channels for all of the members, but still allow the members to read and send messages and be pinged for any messages that @‘s them. This would be useful in servers that include bots such as music so everyone is able to use the music not, but will not be pinged every time someone commands the bot. It would also help to prevent spamming and allow people to feel more confident as they don’t have to feel like they are annoying other members with constant messages.