Add site to HSTS preload list

[cdcadman]

• First set up some basic functionality and test increasing the max-age in the Strict-Transport-Security header.
• Add the site here after following the requirements: https://hstspreload.org/

[cdcadman]

HSTS Preload has been around for a while, and it is easy to obtain certificates for domains and subdomains used with Azure WebApps, so I think it's safe to turn on HSTS Preload right away. This link mentions some risks: https://www.tunetheweb.com/blog/dangerous-web-security-features/