Theme for vgsr.nl since 2016.
If you download Zeta manually, make sure it is uploaded to "/wp-content/themes/zeta/".
Activate Zeta in the "Themes" admin panel using the "Activate" link.
This theme is not hosted in the official WordPress repository. Instead, updating is supported through use of the GitHub Updater plugin by @afragen and friends.
You can contribute to the development of this theme by opening a new issue to report a bug or request a feature in the theme's GitHub repository.