Enable SSL / HTTPS for the web server

[HenrikBengtsson]

Enable SSL / HTTPS for the web server. See https://letsencrypt.org.

[HenrikBengtsson]

This is running on a a2hosting.com server with a grandfathered plan, which does not support SSL. Need to upgrade plan, which might break things. Until I've had time to make sure I can make the migration without wreaking havoc, this needs to wait.

[HenrikBengtsson]

Since it's all static content, maybe moving the site to GitHub Pages is a solution. It's possible to use custom domains and *.github.io GitHub pages do support SSL. However, it doesn't look like one can use SSL on custom domains, e.g. isaacs/github#156. Hmm...