add index accessor for index writer (#1159)
add index accessor for index writer (#1159)

* add index accessor for index writer

* Update src/indexer/index_writer.rs

Co-authored-by: Paul Masurel <a027184a55211cd23e3f3094f1fdc728df5e0500@quickwit.io>
tantivy-search/tantivy,tantivy-search/tantivy