minor #13630 [Docs][Catalog Promotion] Warning added to docs (AdamKasp)

This PR was merged into the 1.11 branch.

Discussion
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| Q               | A
| --------------- | -----
| Branch?         | 1.11
| Bug fix?        | no
| New feature?    | no
| BC breaks?      | no
| License         | MIT

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 To be sure you are not breaking any Backward Compatibilities, check the documentation:
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Commits
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aeed988 Add warning to catalog promotion docs

docs/book/products/catalog_promotions.rst

@@ -313,6 +313,8 @@ After changes in CatalogPromotion, we dispatch proper message with delay calcula
     To enable asynchronous Catalog Promotion, remember about running messenger consumer in a separate process, use the command: ``php bin/console messenger:consume main``
     For more information check official `Symfony docs <https://symfony.com/doc/current/messenger.html#consuming-messages-running-the-worker>`_
 
+    Be aware that loading Catalog Promotion without enabled consumer, will change promotion's state to `active` but products will not be discounted.
+
 How the Catalog Promotions are applied?
 ---------------------------------------