Add license and Google attribution

ATTRIBUTION.md

@@ -0,0 +1,7 @@
+# Attribution
+
+Portions of this project's documentation are modifications based on the [Google developer documentation style guide](https://developers.google.com/style/), created and shared by Google LLC under the [Creative Commons Attribution 4.0 International License](https://creativecommons.org/licenses/by/4.0/legalcode.en).
+
+Changes were made to select, reorganize, summarize, and adapt the source guidance for an AI skill. The adapted material appears primarily in [`references/writing-standard.md`](references/writing-standard.md) and informs related instructions elsewhere in the documentation.
+
+This is an independent project. Google does not sponsor or endorse it. Google's trademarks and other brand features are not included in the Creative Commons license.

LICENSE

@@ -0,0 +1,48 @@
+# License
+
+This repository uses separate licenses for its documentation and software.
+
+## Documentation
+
+Copyright (c) 2026 Nate B. Jones
+
+The documentation is licensed under the [Creative Commons Attribution 4.0 International License](https://creativecommons.org/licenses/by/4.0/legalcode.en) (`CC BY 4.0`). This license applies to:
+
+- `README.md`;
+- `SKILL.md`;
+- `docs/`; and
+- `references/`.
+
+CC BY 4.0 permits sharing and adaptation for any purpose, including commercial use, subject to its attribution and other terms.
+
+Some documentation includes modified material from Google. That material remains subject to Google's license. See [ATTRIBUTION.md](ATTRIBUTION.md) for its source, license, and modification notice.
+
+## Software
+
+The software in `scripts/`, `tests/`, and `.github/workflows/` is licensed under the MIT License:
+
+MIT License
+
+Copyright (c) 2026 Nate B. Jones
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+## Third-party material
+
+Third-party material retains its original license. Nothing in this repository grants rights to Google's trademarks or other brand features.

README.md

@@ -6,7 +6,7 @@ The skill reads the working system before it writes. It separates implemented be
 
 ## Download the skill
 
-Download [developer-documentation-skill-1.0.0.zip](https://github.com/NateBJones-Projects/developer-documentation-skill/releases/download/v1.0.0/developer-documentation-skill-1.0.0.zip) from the first release. The ZIP contains one complete `developer-documentation` directory that you can place in your AI host's skill directory.
+Download [developer-documentation-skill-1.0.1.zip](https://github.com/NateBJones-Projects/developer-documentation-skill/releases/download/v1.0.1/developer-documentation-skill-1.0.1.zip) from the latest release. The ZIP contains one complete `developer-documentation` directory that you can place in your AI host's skill directory.
 
 To follow the project or contribute changes, clone the repository:
 
@@ -32,6 +32,8 @@ Use the skill for:
 
 ```text
 developer-documentation/
+├── ATTRIBUTION.md
+├── LICENSE
 ├── README.md
 ├── SKILL.md
 ├── docs/
@@ -94,6 +96,14 @@ The validator does not prove that technical claims are correct or that commands
 - Python 3 only when you use the validator or run its tests.
 - No third-party Python packages.
 
+## License and attribution
+
+The documentation is licensed under [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/). The validator, tests, and GitHub workflow are licensed under the MIT License. Both licenses permit commercial use.
+
+Portions of the documentation adapt the [Google developer documentation style guide](https://developers.google.com/style/). See [ATTRIBUTION.md](ATTRIBUTION.md) for the source, modification notice, and terms. This project is independent and is not endorsed by Google.
+
+See [LICENSE](LICENSE) for the file-by-file license boundary.
+
 ## Test the package
 
 From the directory that contains `developer-documentation`, run: