message: Update docs to reflect v1 testing syntax
diff: @@ -49,13 +49,13 @@ If you'd like to test your stack code itself without deploying anything you can
  Here is an example test
  ```ts
  -import { Stack, App } from "@serverless-stack/resources"
  +import { App, getStack } from "@serverless-stack/resources"
  import { Template } from "aws-cdk-lib/assertions"
  test("queue exists", async () => {
  const app = new App()
  - const stack = new MyStack(app)
  - const template = Template.fromStack(MyStack);
  + app.stack(MyStack)
  + const template = Template.fromStack(getStack(MyStack));
  template.resourceCountIs("AWS::SQS::Queue", 1);
  });
  ```
  