chore: adapt changes to licence and legal docs

[FaGru3n]

Description

• Add a new file LICENSE_non-code in your repository root with the contents of the CC-BY-4.0 license
• Add the "Project Licenses" and "Terms of Use" sections to your CONTRIBUTING.md file.
• Adapt "Declared Project License" section in NOTICE.md.

closes #24

Pre-review checks

Please ensure to do as many of the following checks as possible, before asking for committer review:

• DEPENDENCIES are up-to-date. Dash license tool. Committers can open IP issues for restricted libs.
• Copyright and license header are present on all affected files