add-ons docs talk about using Codenotary CAS, but that seems to be a dead service / proprietary product offering

[wez]

I can't find any live information on the internet about CAS; all the links seem to be dead or timeout. Is this really a current thing that is used by home assistant?

Please update the docs:

• If CAS is still a thing that can be used, update with current information on how to notarize
• If CAS is no longer a thing, update to remove references to it

[wez]

Relevant:

• https://github.com/home-assistant/builder/issues/162