You could use command-line version of git or GUI version of git, either way is fine.
- Windows/Mac/Linux: https://git-scm.com/downloads
- Windows/Mac: https://desktop.github.com/
- Open the terminal on Windows/Mac/Linux
$ git clone https://github.com/dogecoinfoundation/dogecoin.com.git .
- Open Github Desktop
- Add -> Clone Repository
- URL: https://github.com/dogecoinfoundation/dogecoin.com.git
- Clone it to your local machine