arrow files are supported (huggingface#1225)

* arrow files are supported

* Update docs/hub/datasets-adding.md

Co-authored-by: Quentin Lhoest <42851186+lhoestq@users.noreply.github.com>

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Co-authored-by: Quentin Lhoest <42851186+lhoestq@users.noreply.github.com>

Author: severo

docs/hub/datasets-adding.md

@@ -81,6 +81,7 @@ The Hub natively supports multiple file formats:
 - CSV (.csv, .tsv)
 - JSON Lines, JSON (.jsonl, .json)
 - Parquet (.parquet)
+- Arrow streaming format (.arrow)
 - Text (.txt)
 - Images (.png, .jpg, etc.)
 - Audio (.wav, .mp3, etc.)