The angularjs.org site is not designed to be used by third parties. It is only kept here as part of our own deployment processes.
If you want to have a go at hosting it yourself you can try running
npm run build
but we will not be providing support for doing this.
The site relies upon accessing numerous additional resources from all over the web.
Hint: to access the AngularJS docs application rather than this site, which is only the homepage, clone the main project and build the docs yourself...
git clone https://github.com/angular/angular.js.git cd angular.js npm install grunt package webserver
Then browse to http://localhost:8000/build/docs/api