DEVDOCS-6158: [update] update key description (#683)

<!-- Ticket number or summary of work -->
# [DEVDOCS-6158]


## What changed?
Updated the description of key to prevent confusion

## Release notes draft

Enhancement
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language. Don't be too technical. Explain how the change will benefit
the merchant and link to the feature.

Examples:
* The newly-released [X feature] is now available to use. Now, you’ll be
able to [perform Y action].
* We're happy to announce [X feature], which can help you [perform Y
action].
* [X feature] helps you to create [Y response] using the [Z query
parameter]. Now, you can deliver [ex, localized shopping experiences for
your customers].
* Fixed a bug in the [X endpoint]. Now the [Y field] will appear when
you click [Z option]. -->
* 

## Anything else?
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ping {names}


[DEVDOCS-6158]:
https://bigcommercecloud.atlassian.net/browse/DEVDOCS-6158?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

reference/widgets.v3.yml

@@ -1754,7 +1754,7 @@ components:
                       properties:
                         key:
                           type: string
-                          description: The ID of the `setting` object the conditional attribute is related to.
+                          description: The ID of the `settings` object the conditional attribute is related to. The key must be defined within the same settings array as the conditional property. This ensures the conditional logic is scoped to the relevant settings group.
                           example: backgroundType
                         operator:
                           type: string
@@ -1955,7 +1955,7 @@ components:
                 properties:
                   key:
                     type: string
-                    description: The ID of the `setting` object the conditional attribute is related to.
+                    description: The ID of the `settings` object the conditional attribute is related to. You must define the key within the same settings array as the conditional property to scope the conditional logic to the relevant settings group.
                     example: backgroundType
                   operator:
                     type: string
@@ -1983,7 +1983,7 @@ components:
       properties:
         key:
           type: string
-          description: The ID of the `setting` object the conditional attribute is related to.
+          description: The ID of the `settings` object the conditional attribute is related to. You must define the key within the same settings array as the conditional property to scope the conditional logic to the relevant settings group.
           example: backgroundType
         operator:
           type: string