An example of how to write an AngularJS directive that uses the D3.js visualization library. I walk through building this app on my blog.
Github's Content Security Policy forbids making requests from file://, so you'll need to host the app locally. The easiest way to do this is to launch a simple python server from the directory:
python -m SimpleHTTPServer
If you want to host this application somewhere, note that you have to register the application so it can use the Github API: https://github.com/settings/applications