fix: override rollupOptions.ouput.manualChunks from the user config (#58)

Author: SIGSTACKFAULT

src/index.ts

@@ -82,6 +82,11 @@ function vitePreprocessor(
           formats: ['umd'],
           name: filenameWithoutExtension,
         },
+        rollupOptions: {
+          output: {
+            manualChunks: undefined, // override any manualChunks from the user config because they don't work with UMD
+          }
+        }
       },
     }