fix(types): support node16 and bundler

Currently, the TypeScript types for this module only support the
`node10` TypeScript module resolution mode.
Now, `node10`, `node16` (ESM only), and `bundler` all work,
according to https://arethetypeswrong.github.io/

Fixes: #628
Fixes: #633
Co-authored-by: Andrew Shaw Care <54861+andrewshawcare@users.noreply.github.com>

package.json

@@ -12,7 +12,14 @@
   "engines": {
     "node": "^14.13 || >=16.0"
   },
-  "exports": "./src/index.js",
+  "exports": {
+    ".": {
+      "import": {
+        "types": "./dist-types/src/index.d.ts",
+        "default": "./src/index.js"
+      }
+    }
+  },
   "types": "./dist-types/src/index.d.ts",
   "scripts": {
     "prepare": "tsc && vite build",