Create README.md (Azure#17862)

* Create README.md

Author: RickWinter

sdk/internal/README.md

@@ -0,0 +1,23 @@
+# Azure.Core Internal Module for Go
+
+[![PkgGoDev](https://pkg.go.dev/badge/github.com/Azure/azure-sdk-for-go/sdk/internal)](https://pkg.go.dev/github.com/Azure/azure-sdk-for-go/sdk/internal)
+
+This module contains shared code for the Azure SDK.
+
+## Contributing
+This project welcomes contributions and suggestions. Most contributions require
+you to agree to a Contributor License Agreement (CLA) declaring that you have
+the right to, and actually do, grant us the rights to use your contribution.
+For details, visit [https://cla.microsoft.com](https://cla.microsoft.com).
+
+When you submit a pull request, a CLA-bot will automatically determine whether
+you need to provide a CLA and decorate the PR appropriately (e.g., label,
+comment). Simply follow the instructions provided by the bot. You will only
+need to do this once across all repos using our CLA.
+
+This project has adopted the
+[Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/).
+For more information, see the
+[Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/)
+or contact [[email protected]](mailto:[email protected]) with any
+additional questions or comments.