Update _posts/2019-05-02-zarr-2.3-release.md

Co-Authored-By: alimanfoo <[email protected]>

Author: jakirkham

_posts/2019-05-02-zarr-2.3-release.md

@@ -38,7 +38,7 @@ TODO
 
 Support for other cloud object storage storage services was already
 available via other packages, with Amazon S3 supported via the
-[s3fs](@@TODO) package, and Google Cloud Storage supported via the
+[s3fs]( http://s3fs.readthedocs.io/en/latest/ ) package, and Google Cloud Storage supported via the
 [gcsfs]( https://gcsfs.readthedocs.io/en/latest/ ) package.
 
 The attraction of cloud storage is that total I/O bandwidth scales