Add precision

Issue in ./help/main/c-experiences/c-manage-content/offer-redirect.md

For this part: Redirect offers result in an infinite loop if the redirect URL also qualifies the user for the same activity. Ensure that the user does not re-qualify for the activity after being redirected.

No customer understands what needs to be done as this is not clear enough. I spoke with CC engineering (Bennet) and customer could add a query parameter to the redirecting URL (like: ?redirect=true), and in the activity audience OR in the template rule, customer should check that this query parameter is not present...

Open help/main/c-experiences/c-manage-content/offer-redirect.md and review the paragraph about redirect offers causing an infinite loop. Clarify the suggested query parameter approach, including checking that the parameter is absent in the activity audience or template rule. Done means the documentation clearly tells customers how to prevent re-qualification after a redirect.

Written by the indexing model from the issue text.