Clarify the license(s) for the site

We need to clarify what the license or licenses are for this site. The package.json file states that the license is EPL-2.0 and the site footer states that all rights are reserved. We will need to reconcile these two statements and be specific about which licenses apply to which parts.

We can use the notice file from the asciidoc-lang repository as a reference. See https://gitlab.eclipse.org/eclipse/asciidoc-lang/asciidoc-lang/-/blob/main/NOTICE.adoc

Here is the breakdown I'm proposing:

• The source code, which includes build scripts, Eleventy.js extensions, CSS files, JavaScript code for user interactions, and asset optimization scripts, are licensed under the terms of the EPL-2.0
• The written content, source code examples, and screenshots displayed on the site that is defined in the AsciiDoc files in the pages folder are licensed under the terms of a Creative Commons Attribution 4.0 International License
• The site design and AsciiDoc brand assets are all rights reserved and may not be reproduced anywhere other than asciidoc.org or its deploy previews.

Is there anything that these license notices don't cover?