title: AWS SAM template with multiple MSK topics
body: <p>I have a Lambda function which tiggers off 3 MSK topics.</p>
  <p>I have found I can easily define this dependency in my template.yaml, but only for 1 topic:</p>
  <pre><code>Resources:
    MyFunction:
      Type: AWS::Serverless::Function
      Properties:
        CodeUri: src/
           ...
           MSKEvent:
            Type: MSK
            Properties:
              MaximumBatchingWindowInSeconds: 1
              StartingPosition: LATEST
              Stream: arn:aws:kafka:.....
              Topics:
                - myTopicName
  </code></pre>
  <p>If I try to add more topics <code>sam build</code> will fail saying my template is invalid. I have tried, and failed, providing my topics in these 2 ways:</p>
  <pre><code>Topics:
    - myTopicName
    - myTopicName2
    - myTopicName3
  </code></pre>
  <pre><code>Topics:
    - myTopicName, myTopicName2, myTopicName3
  </code></pre>
  <p><strong>How do I add multiple MSK topics to my SAM template?</strong></p>