build(ExportMap): Add "default" entry
build(ExportMap): Add "default" entry

https://nodejs.org/api/packages.html#conditional-exports

> "default" - the generic fallback that always matches. Can be a CommonJS or ES module file. This condition should always come last.

InsightSoftwareConsortium/ITKBridgeJavaScript,InsightSoftwareConsortium/ITKBridgeJavaScript,InsightSoftwareConsortium/ITKBridgeJavaScript