Download entire website like Apple's Developer Documentation on MacOS

1). Download and install SiteSucker application (the app is working fine on MacOS Sierra)

2). Open the app and click on the Settings icon then select Path pane and Paths to Exclude

3). Paste the following URLs (contains regular expressions) in the listbox

https://developer.apple.com/documentation/[a-rt-z].*
https://developer.apple.com/documentation/s[a-vx-z].*
 

4). Check the "Use Regular Expressions" checkbox

The URL patterns above allows me to download https://developer.apple.com/documentation/swift and any necessary resource files (JS, CSS, images, etc.) under or outside the directory. It won't download the other URLs such as:

https://developer.apple.com/documentation/foundation
https://developer.apple.com/documentation/mapkit
https://developer.apple.com/documentation/uikit
https://developer.apple.com/documentation/gamekit