doc: Update README.md (#5471)

Reinstating ToU. unicode-org/.github#17

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README.md

@@ -86,3 +86,5 @@ Copyright © 2020-2024 Unicode, Inc. Unicode and the Unicode Logo are registered
 The project is released under [LICENSE](./LICENSE), the free and open-source [Unicode License](https://www.unicode.org/license.txt), which is based on the well-known MIT license, with the primary difference being that the Unicode License expressly covers data and data files, as well as code. For further information please see [The Unicode Consortium Intellectual Property, Licensing, and Technical Contribution Policies](https://www.unicode.org/policies/licensing_policy.html).
 
 A CLA is required to contribute to this project - please refer to the [CONTRIBUTING.md](./CONTRIBUTING.md) file (or start a Pull Request) for more information.
+
+The contents of this repository are governed by the Unicode [Terms of Use](https://www.unicode.org/copyright.html).