docs: update README

Author: derrike

README.md

@@ -281,7 +281,7 @@ Be sure to update the `imageRecipeVersion` property when making updates to your
 
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-Specify an alias via the `kmsKeyAlias` property which will be used to encrypt the SNS topic.
+Specify a KMS Key via the `kmsKey` property which will be used to encrypt the SNS topic.
 
 ### Infrastructure Configuration Instance Types