Update critical banner dismiss section (#913)

* Update critical banner dismiss section

Update critical banner dismiss section

* Update content/components/banner.mdx

Co-authored-by: Josh Black <joshblack@github.com>

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Co-authored-by: Josh Black <joshblack@github.com>

content/components/banner.mdx

@@ -200,7 +200,7 @@ Use the following as a guideline:
 >
   <div>
 
-  Critical banners can't be dismissable. They are mostly used for errors which need to be resolved. As a result you can only get rid of a critical banner by resolving the error. If used to warn about   destructive actions, the banner should also not be dismissable.
+  Critical banners communicate an error which the user must resolve in order for the banner to disappear. In certain cases, the banner may be dismissible when notifying the user of a failed action. If used to warn about destructive actions, the banner should also not be dismissible.
 
   If the error must be resolved on a different page, use an action that directs the user to the page where the error can be resolved.