Apply suggestion from @maxrjones

Co-authored-by: Max Jones <14077947+maxrjones@users.noreply.github.com>

Author: d-v-b

docs/contributing.md

@@ -237,4 +237,6 @@ Open an issue on GitHub announcing the release using the release checklist templ
 Zarr uses [pytest-benchmark](https://pytest-benchmark.readthedocs.io/en/latest/) for running
 performance benchmarks as part of our test suite. The benchmarks can be are found in `tests/benchmarks`.
 By default pytest is configured to run these benchmarks as plain tests (i.e., no benchmarking). To run
-a benchmark with timing measurements, use the `--benchmark-enable` when invoking `pytest`.
+a benchmark with timing measurements, use the `--benchmark-enable` when invoking `pytest`.
+
+The benchmarks are run as part of the continuous integration suite through [codspeed](https://codspeed.io/zarr-developers/zarr-python).