Prefer tee -a, not >>, in CI

The blog post advocates for using `tee -a` instead of `>>` in continuous integration scripts, particularly with GitHub Actions. It highlights the benefits of visibility in logs and ease of debugging by showing output values directly in CI logs, making it easier to diagnose issues. While it respects cases where using `>>` might be more appropriate, it suggests adopting `tee -a` as a habit for better introspection in CI workflows.