This will take you to the github file location. Follow the link to the Raw file.
On the raw file page, go to File menu on your browser and click on Save Page As
This will take you to the file save dialogue. Make sure that you save it as any-file-name.ipynb with .ipynb extension. Also make sure that the format is All Files and NOT as text.
Once you start your Jupyter Notebook in the folder with this file, you should be able to open this notebook in the browser.