Update step01_hello_lambda-stack.ts

[fullstackwebdev]

if this isn't set to version 14, this error happens

Step01HelloLambdaStack: creating CloudFormation changeset...
7:54:37 PM | CREATE_FAILED        | AWS::Lambda::Function | HelloHandler2E4FBA4D
Resource handler returned message: "The runtime parameter of nodejs10.x is no longer supported for c
reating or updating AWS Lambda functions. We recommend you use the new runtime (nodejs14.x) while cr
eating or updating functions. (Service: Lambda, Status Code: 400, Request ID: 393b41b6-f4d3-4c7f-b22
f-eafa88563ff9, Extended Request ID: null)" (RequestToken: e6b7577c-7ce4-73d0-3de9-ee2964a897ec, Han
dlerErrorCode: InvalidRequest)