docs(ecs): fixes rosetta extraction errors in the README file (#22646)

When running `yarn rosetta:extract --strict` in `@aws-cdk/aws-ecs` package, there are various errors:

![CleanShot 2022-10-25 at 22 08 55](https://user-images.githubusercontent.com/2566530/197918399-870c9bf6-4279-491f-a69a-654109472a23.png)

This PR fixes all that so the command works.

![CleanShot 2022-10-25 at 22 14 03](https://user-images.githubusercontent.com/2566530/197918475-da87f603-a42f-40a1-9030-77511daa9c29.png)

----

### All Submissions:

* [x] Have you followed the guidelines in our [Contributing guide?](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md)

### Adding new Unconventional Dependencies:

* [ ] This PR adds new unconventional dependencies following the process described [here](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md/#adding-new-unconventional-dependencies)

### New Features

* [ ] Have you added the new feature to an [integration test](https://github.com/aws/aws-cdk/blob/main/INTEGRATION_TESTS.md)?
	* [ ] Did you use `yarn integ` to deploy the infrastructure and generate the snapshot (i.e. `yarn integ` without `--dry-run`)?

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

Author: pallymore

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

@@ -26,9 +26,7 @@ runs a service on it:
 declare const vpc: ec2.Vpc;
 
 // Create an ECS cluster
-const cluster = new ecs.Cluster(this, 'Cluster', {
-  vpc,
-});
+const cluster = new ecs.Cluster(this, 'Cluster', { vpc });
 
 // Add capacity to it
 cluster.addCapacity('DefaultAutoScalingGroupCapacity', {
@@ -171,6 +169,7 @@ const autoScalingGroup = new autoscaling.AutoScalingGroup(this, 'ASG', {
 To use `LaunchTemplate` with `AsgCapacityProvider`, make sure to specify the `userData` in the `LaunchTemplate`:
 
 ```ts
+declare const vpc: ec2.Vpc;
 const launchTemplate = new ec2.LaunchTemplate(this, 'ASG-LaunchTemplate', {
   instanceType: new ec2.InstanceType('t3.medium'),
   machineImage: ecs.EcsOptimizedImage.amazonLinux2(),
@@ -424,7 +423,7 @@ To grant a principal permission to run your `TaskDefinition`, you can use the `T
 
 ```ts
 declare const role: iam.IGrantable;
-const taskDef = new ecs.TaskDefinition(stack, 'TaskDef', {
+const taskDef = new ecs.TaskDefinition(this, 'TaskDef', {
   cpu: '512',
   memoryMiB: '512',
   compatibility: ecs.Compatibility.EC2_AND_FARGATE,
@@ -501,7 +500,7 @@ taskDefinition.addContainer('container', {
   linuxParameters: new ecs.LinuxParameters(this, 'LinuxParameters', {
     initProcessEnabled: true,
     sharedMemorySize: 1024,
-    maxSwap: 5000,
+    maxSwap: Size.mebibytes(5000),
     swappiness: 90,
   }),
 });
@@ -890,7 +889,7 @@ taskDefinition.addContainer('TheContainer', {
 ### splunk Log Driver
 
 ```ts
-declare const secret: secretsmanager.Secret;
+declare const secret: ecs.Secret;
 
 // Create a Task Definition for the container to start
 const taskDefinition = new ecs.Ec2TaskDefinition(this, 'TaskDef');

packages/@aws-cdk/aws-ecs/rosetta/default.ts-fixture

@@ -1,6 +1,6 @@
 // Fixture with packages imported, but nothing else
 import { Construct } from 'constructs';
-import { SecretValue, Stack } from '@aws-cdk/core';
+import { SecretValue, Stack, Size } from '@aws-cdk/core';
 import autoscaling = require('@aws-cdk/aws-autoscaling');
 import cloudmap = require('@aws-cdk/aws-servicediscovery');
 import ecs = require('@aws-cdk/aws-ecs');
@@ -14,6 +14,7 @@ import s3 = require('@aws-cdk/aws-s3');
 import secretsmanager = require('@aws-cdk/aws-secretsmanager');
 import ssm = require('@aws-cdk/aws-ssm');
 import targets = require('@aws-cdk/aws-events-targets');
+import iam = require('@aws-cdk/aws-iam');
 import path = require('path');
 
 class Fixture extends Stack {