We've updated the link from https://developer.apple.com/library/archive/documentation/Tools/Conceptual/SafariExtensionGuide/Introduction/Introduction.html https

We've updated the link from https://developer.apple.com/library/archive/documentation/Tools/Conceptual/SafariExtensionGuide/Introduction/Introduction.html https://developer.apple.com/library/archive/documentation/To... to this, which has more detail.