Update privacy link in readme and add Consumer Health Privacy notice on website

[jackgerrits]

Why are these changes needed?

• The privacy notice should be navigated to via the redirect (as is done in the website footer)
• Added required noticed on Consumer Health Privacy

Related issue number

Checks

• I've included any doc changes needed for https://microsoft.github.io/autogen/. See https://microsoft.github.io/autogen/docs/Contribute#documentation to build and test documentation locally.
• I've added tests (if relevant) corresponding to the changes introduced in this PR.
• I've made sure all auto checks have passed.