synthetics/cloudformation_include: screenshot not displayed in documentation

### Describe the issue

The [synthetics documentation](https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.aws_synthetics-readme.html) contains an image that cannot be loaded:

Similar issue in the [cloudformation_include](https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.cloudformation_include-readme.html) documentation:

To be discussed:
I can't find another page that uses images. Probably images are not supported in the CDK documentation. Can this be fixed? Or should we just remove these images from the module readme files?

### Links

https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.aws_synthetics-readme.html
https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.cloudformation_include-readme.html

Compare the linked synthetics and cloudformation_include documentation pages with their corresponding module README files, focusing on how the embedded images are referenced. First determine from the CDK documentation generation guidance whether images are supported; done means both pages display their images correctly or the unsupported image references are removed.

Written by the indexing model from the issue text.