Add type: "module" to package.json

Author: timolins

package.json

@@ -5,9 +5,10 @@
   "author": "Timo Lins",
   "license": "MIT",
   "repository": "timolins/little-date",
-  "main": "dist/format-date-range.js",
-  "module": "dist/format-date-range.mjs",
-  "types": "dist/format-date-range.d.ts",
+  "type": "module",
+  "main": "./dist/format-date-range.js",
+  "module": "./dist/format-date-range.mjs",
+  "types": "./dist/format-date-range.d.ts",
   "engines": {
     "node": ">=10"
   },