Update _index.md

Using indefinite article for 'create a workload object'

Author: andrewreeman

content/en/docs/concepts/workloads/controllers/_index.md

@@ -13,7 +13,7 @@ Ultimately, your applications run as containers inside
 Pods would be a lot of effort. For example, if a Pod fails, you probably want to
 run a new Pod to replace it. Kubernetes can do that for you.
 
-You use the Kubernetes API to create workload
+You use the Kubernetes API to create a workload
 {{< glossary_tooltip text="object" term_id="object" >}} that represent a higher level
 abstraction than a Pod, and then the Kubernetes
 {{< glossary_tooltip text="control plane" term_id="control-plane" >}} automatically manages