[zh] fixed typo

Author: Arhell

content/zh/docs/setup/production-environment/_index.md

@@ -10,7 +10,7 @@ no_list: true
 A production-quality Kubernetes cluster requires planning and preparation.
 If your Kubernetes cluster is to run critical workloads, it must be configured to be resilient.
 This page explains steps you can take to set up a production-ready cluster,
-or to uprate an existing cluster for production use.
+or to promote an existing cluster for production use.
 If you're already familiar with production setup and want the links, skip to
 [What's next](#what-s-next).
 -->