Add and improve comments of the `IndexIterator`
Add and improve comments of the `IndexIterator`

algolia/algoliasearch-client-go,l4u/algoliasearch-client-go,l4u/algoliasearch-client-go,algoliareadmebot/algoliasearch-client-go,rastech/algoliasearch-client-go,algolia/algoliasearch-client-go