Add missing exports conditions

[laxadev]

You can find more information about this here https://github.com/sveltejs/vite-plugin-svelte/blob/main/docs/faq.md#missing-exports-condition

[ptrxyz]

With latest versions of Svelte, this is required and throws nasty warnings all day long.

The fix is super simple, simply add the exports object to the package.json and it's all good:

...
"svelte": "dist/index.js",
  "exports": {
    ".": {
      "types": "./dist/ts/index.d.ts",
      "svelte": "./dist/index.js"
    }
  },
...

edit: added types

[ptrxyz]

Added PR: #52