fix: declare exports explicitly

Author: djcsdy

package.json

@@ -14,6 +14,9 @@
   "bugs": "https://github.com/softwareventures/resolve-typescript-plugin/issues",
   "repository": "github:softwareventures/resolve-typescript-plugin",
   "license": "ISC",
+  "exports": {
+    ".": "./index.js"
+  },
   "types": "index.d.ts",
   "scripts": {
     "fix": "tsc --noEmit && eslint . --fix && prettier --write .",