Add sample copy that can be used to alert site visitor's that AI tools are in use

[dkotter]

Description of the Change

It's ideal to let site visitor's know when AI tools may be in use. This can be fairly straightforward if using AI to write content or to generate images but if used to do things like generate an excerpt, add alt text or classify content there's not necessarily a great place to put these alerts.

The easiest answer is to add a section in your site's Privacy Policy / Terms of Use / similar type of page that let's visitors know that AI tools may be in use. This PR adds sample copy to our README.md file that can be used for this purpose. In addition, it utilizes the core wp_add_privacy_policy_content function to add the same copy to the Privacy admin settings page, allowing users to copy/paste from there:

Closes #480

How to test the Change

1. Verify the changes to the README.md file look correct
2. Verify the changes show in the WordPress Privacy admin page

Changelog Entry

Added - Provide sample copy that can be added to a site's Privacy Policy, letting site visitors know AI tools are in use

Credits

Props @jeffpaul, @dkotter

Checklist:

• I agree to follow this project's Code of Conduct.
• I have updated the documentation accordingly.
• I have added tests to cover my change.
• All new and existing tests pass.

[jeffpaul]

Generally on-board with the changes here; I left a couple comments for some potential iterations on the copy, open to keeping what's already there or iterating in some manner if my thoughts seem rational to others?

[jeffpaul]

Should be good to go, thanks!