Mention pyarrow to use parquet format.

README.md

@@ -131,10 +131,16 @@ I haven't tried it yet as of September 2024.
 
 URL: <https://www.pola.rs/>
 
+### pyarrow
+
+Library to use the highly efficient Apache Parquet file format from scipy and pandas.
+I haven't tried it yet as of November 2024.
+
+URL: <https://arrow.apache.org/docs/python/index.html>
+
 ### anndata
 
 Another alternative for pandas?
-
 I haven't tried it.
 
 URL: <https://anndata.readthedocs.io/en/latest/>