Add export for helpers

[Mangatt]

It would be nice to have exports for helpers mentioned in docs. Right now it's something like that:

import nextCloudHelper from 'nextcloud-link/compiled/helper'
const { createOwnCloudFileDetailProperty } = nextCloudHelper

It would be better to have:

import { createOwnCloudFileDetailProperty } from 'nextcloud-link'

or

import { createOwnCloudFileDetailProperty } from 'nextcloud-link/helpers'

[kwisatz]

I'll leave this for one of the devs to answer, but as you can imagine, @Mangatt, we're not opposed to you creating a PR for this.