Fix typings resolution when using TypeScript 4.7+ with ESM

TypeScript in ESM mode is trying to use file index.d.mts for types but there is no such file. So we need to provide custom path to typings file. Root `types` field is ignored in ESM mode

Author: Nitive

package.json

@@ -7,7 +7,8 @@
   "exports": {
     ".": {
       "import": "./mjs/index.js",
-      "require": "./cjs/index.js"
+      "require": "./cjs/index.js",
+      "types": "./index.d.ts"
     }
   },
   "types": "./index.d.ts",