Pushbullet channel error (disabled by default) + readme info

[malosaa]

@jxmorris12 i checked this whole code and it works normal,no errors after 1 hour...

• [x] Bug fix
• [ ] New feature
• [ ] Translation

The following changes were made:

• added new readme info
• changed code in notifier
• no duplicate

[jxmorris12]

there are still merge conflicts buddy