There should be no need to adjust the GitHub configuration. This documents the configuration for posterity and troubleshooting.
There are three choices for the publishing source. We are using the master branch /docs folder option. This is the document root of the website.
The website is using https://www.tcsh.org/ as its canonical address. The custom domain is set using a CNAME file.
A custom domain name could also be set from the GitHub web interface but that just edits the CNAME file in the document root, which would get overwritten when regenerating the site.
HTTPS is enabled from the GitHub web interface and only works for the canonical address https://www.tcsh.org/. Trying to access https://tcsh.org/ results in an SSL certificate validation error on the browser.
Typing just tcsh.org
or www.tcsh.org
in the browser address bar
works. You will be redirected to https://www.tcsh.org/ from both.
Note that redirects for custom domains only work over HTTP.
The DNS data has a www CNAME for www.tcsh.org
and A records for tcsh.org
.