Update contributor guide to include language from the template

CONTRIBUTING.md

@@ -1,10 +1,25 @@
 # Contributing
+
+Thank you for contributing to Stoke! This guide will help you get started and know what to expect. All contributions and project spaces are subject to our [Code of Conduct](https://github.com/fidelity/.github/blob/main/CODE_OF_CONDUCT.md).
+
 We welcome all contributions from the community! Any contributions to `stoke` should come through valid Pull Requests 
 in the public open-source repository.
 
+Please open an issue **unless** you are making a significant security disclosure.
+
+## How to disclose security concerns responsibly
+
+Please follow the instructions in our [security policy](https://github.com/fidelity/.github/blob/main/SECURITY.md) (also visible in the Security tab on the project's repo).
+
 ## Contribution Guidelines
 1. Adhere to [PEP-8](https://www.python.org/dev/peps/pep-0008/) standards.
 2. Run black and isort linters before creating a PR.
 3. Any changes to core functionality must pass all existing unit tests.
 4. Additional functionality should have associated unit tests.
-5. Provide documentation ([Numpy Docstring format](https://numpydoc.readthedocs.io/en/latest/format.html#style-guide)) whenever possible, even for simple functions or classes.
+5. Provide documentation ([Numpy Docstring format](https://numpydoc.readthedocs.io/en/latest/format.html#style-guide)) whenever possible, even for simple functions or classes.
+6. Your contribution must be received under the project's open source license.
+7. You must have permission to make the contribution. We strongly recommend including a Signed-off-by line to indicate your adherence to the [Developer Certificate of Origin](https://developercertificate.org/).
+
+## Getting help
+
+If you have other questions about this project, please open an issue. To reach the Fidelity OSPO directly, please email [[email protected]](mailto:[email protected]).