Improve language describing deletion of hooks

The existing language was somewhat confusing and grammatically poor.

Closes #5035

Signed-off-by: Henry Nash <henry.nash@uk.ibm.com>

docs/charts_hooks.md

@@ -248,8 +248,8 @@ annotated.
 
 When a helm release, that uses a hook, is being updated, it is possible that the hook resource might already exist in the cluster. In such circumstances, by default, helm will fail trying to install the hook resource with an `"... already exists"` error.
 
-A common reason why the hook resource might already exist is that it was not deleted following use on a previous install/upgrade. There are, in fact, good reasons why one might want to keep the hook: for example, to aid manual debugging in case something went wrong. In this case, the recommended way of ensuring subsequent attemps to create the hook do not fail is to define a `"hook-delete-policy"` that can handle this: `"helm.sh/hook-delete-policy": "before-hook-creation"`. This hook annotation causes tiller to remove any existing hook, if there is one, before the new hook is installed.
+A common reason why the hook resource might already exist is that it was not deleted following use on a previous install/upgrade. There are, in fact, good reasons why one might want to keep the hook: for example, to aid manual debugging in case something went wrong. In this case, the recommended way of ensuring subsequent attemps to create the hook do not fail is to define a `"hook-delete-policy"` that can handle this: `"helm.sh/hook-delete-policy": "before-hook-creation"`. This hook annotation causes any existing hook to be removed, before the new hook is installed.
 
-If it prefered to actually delete the hook after each use (rather than have to handle it on a subsequent use, as shown above), then this can be achived using a delete policy of `"helm.sh/hook-delete-policy": "hook-succeeded,hook-failed"`.
+If it is preferred to actually delete the hook after each use (rather than have to handle it on a subsequent use, as shown above), then this can be achived using a delete policy of `"helm.sh/hook-delete-policy": "hook-succeeded,hook-failed"`.