Create validation script for api-extractor.json to consistently publish API docs for public components

[kuhe]

Describe the issue

On our API docs site, some symbols don't link to anything. This makes discovery very difficult unless you read the API through your actual code editor.

The validation should do the following:

• if any code object in a package has the @public typedoc annotation, the package should have an api-extractor.json metadata so its types can be published to the API doc website.

Links

https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/Package/-smithy-smithy-client/Class/Command/

[kuhe]

Context: we reduced the number of packages published to the API docs website to reduce the chances of users getting lost.

Not all package exported symbols are considered public API. But those that are should be published to the site.