* Add rel=noopener to the github link to prevent window.opener attacks.
* Add no-referrer referrer policy to prevent leakage of sensitive info such as private domain names.
This prevents Referer headers from being sent when requesting any
external assets, and when clicking on any offsite links. This includes
the github link in the footer. This helps to prevent the leakage of
sensitive details, such as private domain names.
Matthew Gamble
Thor77