Describe the bug

See aws/aws-cdk#20623

Missing code block causes CDK documentation to be corrupted. In addition to fixing the instance, we should try to throw an error if this happens.

Expected Behavior

An error thrown, or some way to make sure the documentation that shows up is not corrupted

Current Behavior

Weird documentation shows up.

Reproduction Steps

See aws/aws-cdk#20623

Possible Solution

No response

Additional Information/Context

No response

SDK version used

CDK

Environment details (OS name and version, etc.)

MacOs