This method is little tricky but it works. You only requires google chrome browser to download offline version of angular.io website. The steps are as follows: Open angular.io in chrome browser. Open all the pages at least once that you wanted to be available for offline reading. The pages will cached in browser. Now goto More tools > Add to Desktop and click add. Your offline version of angular.io is on desktop. Try it after disconnecting from the internet. Note: If you have not opened all the pages before step 3. There is no problem. Reconnect to internet and open all those links in the added shortcut on the desktop.
Tips and Tricks to make your Angular life Easy and Simple