Add PRQLto list of users (#1031)

Co-authored-by: Andrew Lamb <[email protected]>

README.md

@@ -93,7 +93,7 @@ $ cargo run --features json_example --example cli FILENAME.sql [--dialectname]
 ## Users
 
 This parser is currently being used by the [DataFusion] query engine,
-[LocustDB], [Ballista], [GlueSQL], [Opteryx], and [JumpWire].
+[LocustDB], [Ballista], [GlueSQL], [Opteryx], [PRQL], and [JumpWire].
 
 If your project is using sqlparser-rs feel free to make a PR to add it
 to this list.
@@ -188,6 +188,7 @@ licensed as above, without any additional terms or conditions.
 [Ballista]: https://github.com/apache/arrow-ballista
 [GlueSQL]: https://github.com/gluesql/gluesql
 [Opteryx]: https://github.com/mabel-dev/opteryx
+[PRQL]: https://github.com/PRQL/prql
 [JumpWire]: https://github.com/extragoodlabs/jumpwire
 [Pratt Parser]: https://tdop.github.io/
 [sql-2016-grammar]: https://jakewheat.github.io/sql-overview/sql-2016-foundation-grammar.html