fix: bring back preserve modules

Author: logaretm

dev-packages/rollup-utils/npmHelpers.mjs

@@ -52,6 +52,9 @@ export function makeBaseNPMConfig(options = {}) {
       // Include __esModule property when there is a default prop
       esModule: 'if-default-prop',
 
+      // output individual files rather than one big bundle
+      preserveModules: true,
+
       // Allow wrappers or helper functions generated by rollup to use any ES2015 features
       generatedCode: {
         preset: 'es2015',