These github icons are downloaded and used according to the instructions here:

<https://github.com/logos>

```sh
$ wget https://github-media-downloads.s3.amazonaws.com/GitHub-Mark.zip
$ sha256sum ./GitHub-Mark.zip
69a785315ad17420accffc9321803ab7825f30a410003339d07cf3092893f687 ./GitHub-Mark.zip
````

The files used under this zip archive are:

```
GitHub-Mark/
└── PNG
    ├── GitHub-Mark-64px.png
    └── GitHub-Mark-Light-64px.png
```