Update README.md (#77)

Based on https://github.com/awslabs/aws-solutions-constructs/blob/a3b6e0f26cec71db0ad33a3534dd17963e0dfa30/source/patterns/%40aws-solutions-constructs/aws-apigateway-lambda/lib/index.ts#L50 name of the property should be `apiGateway`

source/patterns/@aws-solutions-constructs/aws-apigateway-lambda/README.md

@@ -66,7 +66,7 @@ _Parameters_
 | **Name**     | **Type**        | **Description** |
 |:-------------|:----------------|-----------------|
 |lambdaFunction|[`lambda.Function`](https://docs.aws.amazon.com/cdk/api/latest/docs/@aws-cdk_aws-lambda.Function.html)|Returns an instance of the Lambda function created by the pattern.|
-|restApi|[`api.LambdaRestApi`](https://docs.aws.amazon.com/cdk/api/latest/docs/@aws-cdk_aws-apigateway.LambdaRestApi.html)|Returns an instance of the API Gateway REST API created by the pattern.|
+|apiGateway|[`api.LambdaRestApi`](https://docs.aws.amazon.com/cdk/api/latest/docs/@aws-cdk_aws-apigateway.LambdaRestApi.html)|Returns an instance of the API Gateway REST API created by the pattern.|
 |apiGatewayCloudWatchRole|[`iam.Role`](https://docs.aws.amazon.com/cdk/api/latest/docs/@aws-cdk_aws-iam.Role.html)|Returns an instance of the iam.Role created by the construct for API Gateway for CloudWatch access.|
 |apiGatewayLogGroup|[`logs.LogGroup`](https://docs.aws.amazon.com/cdk/api/latest/docs/@aws-cdk_aws-logs.LogGroup.html)|Returns an instance of the LogGroup created by the construct for API Gateway access logging to CloudWatch.|
 
@@ -90,4 +90,4 @@ Out of the box implementation of the Construct without any override will set the
 ![Architecture Diagram](architecture.png)
 
 ***
-© Copyright 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+© Copyright 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.