Added simple contribution policy (#63)

* Added simple contribution policy

Signed-off-by: Eddie Knight <knight@linux.com>

* typofix

Signed-off-by: Eddie Knight <knight@linux.com>

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Signed-off-by: Eddie Knight <knight@linux.com>

CONTRIBUTING.md

@@ -0,0 +1,29 @@
+Thank you for your interest in contributing to the Security Insights Specification!
+
+## How to Contribute
+
+1. [Fork](https://docs.github.com/en/get-started/quickstart/fork-a-repo) the repository to your own GitHub account.
+2. Make changes or improvements to the specification document in your forked repository.
+3. Create a [Pull Request](https://docs.github.com/en/get-started/quickstart/opening-a-pull-request) with a clear title and description of your changes.
+
+## Issue Reporting
+
+If you find issues or inconsistencies in the specification, please [open an issue](https://docs.github.com/en/get-started/quickstart/opening-an-issue) with a detailed description.
+
+## Review Process
+
+Our team will review your contributions and provide feedback. Once approved, we'll merge your changes.
+
+Reach out to us on [Slack](https://openssf.slack.com/messages/security_insights) or join a [community meeting](https://calendar.google.com/calendar?cid=czYzdm9lZmhwNWk5cGZsdGI1cTY3bmdwZXNAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ) for the Identifying Security Threats Working Group.
+
+## Code of Conduct
+
+Please adhere to our [Code of Conduct](https://github.com/ossf/.github/CODE_OF_CONDUCT.md) when participating in this project.
+
+## Licensing
+
+By contributing, you agree that your contributions will be licensed under the [project's license](LICENSE.md).
+
+## Thanks!
+
+Thank you for helping improve the Security Insights Specification!