Merge pull request #32 from githubtraining/update-server-instructions

Update server instructions

Author: brianamarie

server-installation-notes.md

@@ -14,3 +14,4 @@ The following are dependencies of the course. The course may continue to work wi
 | [GitHub Pages](https://help.github.com/en/enterprise/admin/installation/configuring-github-pages-on-your-appliance) | Yes       | Used to teach the learner how to enable GitHub Pages, choose a theme, customize, and edit the project.                                                               | This course could be modified to teach Jekyll without GitHub Pages, but it requires significant changes to both `config.yml`, and the `responses/` folder. |
 | GHES must be able to reach githubusercontent.com                                                                         | Yes       | Images used throughout the course are served from this domain. Learners will find broken images required to take the course without this access. | Manually download the images referenced in the `responses/` folder, upload them to an accessible domain, and replace the images in the `responses/` folder.                                                                                                |
 | Learner must be able to reach github.com and outside web                                                                 | No        | Links are provided to resources that live on the outside web.                                                                                  | Without access to resources on the outside web, learners will reach blocked resources. You can change the links to these resources in the `responses/` folder, and in the template repository.                                                             |
+| GHES must be able to reach GitHub.com | Yes | The network must be able to access GitHub.com to access the [`minima` theme](https://pages.github.com/themes/). | If this is not possible, the repository can be recreated within your GHES instance and update the course instructions to point to the new [remote alternative theme](https://help.github.com/en/enterprise/2.14/user/articles/adding-a-jekyll-theme-to-your-github-pages-site). |