Allow users to set "Notify Subscribers"

[JpDeathBlade]

A user might not want every video they upload to notify their subscribers.

As described here: https://developers.google.com/youtube/v3/docs/videos/insert The notifySubscribers parameter indicates whether YouTube should send a notification about the new video to users who subscribe to the video's channel. A parameter value of True indicates that subscribers will be notified of newly uploaded videos. However, a channel owner who is uploading many videos might prefer to set the value to False to avoid sending a notification about each new video to the channel's subscribers. The default value is True.

[kootsoop]

This will require:

• Adding a new command line option
• Validating the command line option
• Setting the appropriate field on video insert