[Docs]: Improve error display | Add better samples for email and sms notifications

[AyresMonteiro]

What's on your mind?

I had to use axios in order to figure out what's happening in my 400 status code request due to errors being show as GenericErrorErrorsInner without clear error messages.

It would be simpler if docs had a sample of sms notification requiring sms_from prop, and an equivalent sample for email notification sending.

I would appreciate it if the documentation was improved in this regard.

Indeed, notification type not contains include_subscription_ids prop.

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