docs(cognito): Fix type names for with*Attributes methods in docs (#1…

…3174)

Closes #13173.


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packages/@aws-cdk/aws-cognito/README.md

@@ -582,12 +582,12 @@ The default behaviour is to allow read and write permissions on all attributes.
 const pool = new cognito.UserPool(this, 'Pool');
 
 const clientWriteAttributes = (new ClientAttributes())
-  .withStandardAttributes({name: true, email: true})
-  .withCustomAttributes(['favouritePizza']);
+  .withStandardAttributes({fullname: true, email: true})
+  .withCustomAttributes('favouritePizza', 'favouriteBeverage');
 
 const clientReadAttributes = clientWriteAttributes
   .withStandardAttributes({emailVerified: true})
-  .withCustomAttributes(['pointsEarned']);
+  .withCustomAttributes('pointsEarned');
 
 pool.addClient('app-client', {
   // ...