Fixes missing export of typescript types, adjusts README

Author: philipstanislaus

README.md

@@ -88,7 +88,7 @@ tree === [
 This project includes types, just import the module as usual:
 
 ```ts
-import * as arrayToTree from 'performant-array-to-tree'
+import { arrayToTree } from 'performant-array-to-tree'
 
 const tree = arrayToTree(array)
 ```

package.json

@@ -3,6 +3,7 @@
   "version": "1.0.0",
   "description": "Converts an array of items with ids and parent ids to a nested tree in a performant `O(n)` way. Runs in browsers and node.",
   "main": "build/arrayToTree.min.js",
+  "types": "build/arrayToTree.d.ts",
   "author": "Philip Stanislaus <[email protected]>",
   "license": "MIT",
   "dependencies": {},