Issue

When using experimentalDts i would like to be able to set non-external packages, which is configured through api-extractor's "bundledPackages" option.
Currently it is not possible to pass any extra configuration into @microsoft/api-extractor.

Possible solutions:

• Allow passing api-extractor config items through "experimentalDts" tsup's config option.

or

• Pass the content of tsup's "noExternal" into the "bundledPackages" api-extractor option.

or

• Detect the existence of an 'api-extractor.json' file, and pass it's content to api-extractor.