[Docs Bug 🐞 report]: Missing docs on secrets (and other resources?)

### Describe the bug you found in LocalStack Docs.

See https://github.com/localstack/localstack/issues/12177 for details.

Issue requested by @alexrashed 

### Attach any resources that can help us understand the issue.

See https://github.com/localstack/localstack/issues/12177 for details

### Code of Conduct

- [x] I agree to follow this project's Code of Conduct