Update persistent-storage.md

Co-authored-by: Copilot <[email protected]>

Author: jbrejner

persistent-storage.md

@@ -277,7 +277,7 @@ Fill in the values:
 - `mountPath` is the path in the container to mount the volume to. For postgres, the database state is
   stored to the path `/var/lib/postgresql/data`
 - `subPath` should be `postgres`, and specifies a directory to be created within the volume. We need
-  this because of a quirk with combining `AWS EBS` with Postgres. (If you are curious, why:
+  this because of a quirk with combining `AWS EBS` with Postgres. (If you are curious why:
   <https://stackoverflow.com/a/51174380>)
 
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