Avoid dual package hazard when Node.js supports require(esm)

Author: fabon-f

package.json

@@ -6,10 +6,12 @@
 	"exports": {
 		".": {
 			"import": "./dist/esm/index.js",
+			"module-sync": "./dist/esm/index.js",
 			"require": "./dist/cjs/index.js"
 		},
 		"./duration": {
 			"import": "./dist/esm/duration/index.js",
+			"module-sync": "./dist/esm/duration/index.js",
 			"require": "./dist/cjs/duration/index.js"
 		}
 	},