Merge pull request #21566 from adamulacha/patch-1

Update configmap.md

Author: k8s-ci-robot

content/en/docs/concepts/configuration/configmap.md

@@ -189,7 +189,7 @@ spec:
       readOnly: true
   volumes:
   - name: foo
-    configmap:
+    configMap:
       name: myconfigmap
 ```