Merge branch 'feature/upgrade' of github.com:stackabletech/hdfs-operator into feature/upgrade

Author: nightkr

docs/modules/hdfs/pages/usage-guide/upgrading.adoc

@@ -96,7 +96,7 @@ Rolling upgrade is finalized.
 
 WARNING: Please ensure that all NameNodes are running and available before proceeding. NameNodes that have not finalized yet will crash on launch when taken out of compatibility mode.
 
-Finally, we mark the cluster as upgraded:
+Finally, mark the cluster as upgraded:
 
 [source,shell]
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