You can turn wikis off for your repository if you decide not to use them.

  1. On GitHub, navigate to the main page of the repository.

  2. Under your repository name, click Settings. Repository settings button

  3. Under Features, unselect Wiki. Wiki disable checkbox

When you turn off a wiki, the content is hidden, but not erased. If you choose to re-enable wikis later, your previous pages will be restored.

Further reading