feat(notification integration): 📝 notification integration doc

[ziracmo]

📝 Notification Integration Documentation

[aws-amplify-eu-west-1]

This pull request is automatically being deployed by Amplify Hosting (learn more).

Access this pull request here: https://pr-767.d1to60jd2gb6y6.amplifyapp.com

[ziracmo]

@AlteredCoder The Webhook documentation should also inform users about the ping that is not available in edition mode

[rr404]

I think we need to add simlple overview sentence at the very beginning to make the pl understand how it works overall and make them intuite what configuration and rules mean. (could be good in general overview too)
--- example but let's work on phrasing a bit ---
Adding an integration will Create an integration configuration specific to your slack workspace.
Then you can add rules to select what event trigger notifications to what slack channel.

---- in just 2 sentence we then clarify that integration is global to the workspace and user should NOT expect to select a channel straight away, also we mention "configuration" and "rules" thus explaining the other tabs of the section

[ziracmo]

@rr404 What do you think of:

"Connecting an integration will create a configuration specific to your Slack workspace.
You can then define rules to control which events trigger notifications and which Slack channel they’re sent to."