Consider using the Expect-CT header for Certificate Transparency on our website

Expect-CT: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Expect-CT
- Certificate Transparency: https://en.wikipedia.org/wiki/Certificate_Transparency

Related issues

Related to #9026 (closed)
Related to #9027 (closed)

Original created by @sajolida on 16675 (Redmine)

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information