tweak

Author: alamb

README.md

@@ -30,7 +30,7 @@ questions, help others, and get involved. All participation in the Apache Arrow
 project is governed by the Apache Software Foundation's [code of
 conduct](https://www.apache.org/foundation/policies/conduct.html).
 
-We use [GitHub issues][issues] for all technical discussions, reviews,
+We use GitHub [issues] and [pull requests] for all technical discussions, reviews,
 new features, bug fixes and release coordiation. This ensures that all communication
 is public and archived for future reference.
 
@@ -60,6 +60,7 @@ Note: previously the [`object_store`] crate was also part of this repository,
 but it has been moved to the [arrow-rs-object-store repository]
 
 [apache arrow]: https://arrow.apache.org/
+[apache parquet]: https://parquet.apache.org/
 [`arrow`]: https://crates.io/crates/arrow
 [`parquet`]: https://crates.io/crates/parquet
 [`parquet_derive`]: https://crates.io/crates/parquet-derive
@@ -186,4 +187,5 @@ You can find more details about each crate in their respective READMEs.
 [ballista-readme]: https://github.com/apache/datafusion-ballista/blob/main/README.md
 [parquet-derive-readme]: parquet_derive/README.md
 [issues]: https://github.com/apache/arrow-rs/issues
+[pull requests]: https://github.com/apache/arrow-rs/pulls 
 [discussions]: https://github.com/apache/arrow-rs/discussions