docs(trigger): fix incorrect construct id in README for aws-cdk-lib.t…

…riggers module (#26436)

README for aws-cdk-lib.triggers module includes incorrect construct id `myLambdaFunction`. 
https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.triggers-readme.html#usage
> In the above example, the AWS Lambda function defined in myLambdaFunction will be invoked when the stack is deployed.

In my understanding, it should be `MyTrigger`.

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/aws-cdk-lib/triggers/README.md

@@ -24,7 +24,7 @@ new triggers.TriggerFunction(this, 'MyTrigger', {
 });
 ```
 
-In the above example, the AWS Lambda function defined in `myLambdaFunction` will
+In the above example, the AWS Lambda function defined in `MyTrigger` will
 be invoked when the stack is deployed.
 
 It is also possible to trigger a predefined Lambda function by using the `Trigger` construct: