config: add rustfmt config

src/hash/rpo/digest.rs

@@ -118,14 +118,13 @@ impl Ord for RpoDigest {
         // finally, we use `Felt::inner` instead of `Felt::as_int` so we avoid performing a
         // montgomery reduction for every limb. that is safe because every inner element of the
         // digest is guaranteed to be in its canonical form (that is, `x in [0,p)`).
-        self.0
-            .iter()
-            .map(Felt::inner)
-            .zip(other.0.iter().map(Felt::inner))
-            .fold(Ordering::Equal, |ord, (a, b)| match ord {
+        self.0.iter().map(Felt::inner).zip(other.0.iter().map(Felt::inner)).fold(
+            Ordering::Equal,
+            |ord, (a, b)| match ord {
                 Ordering::Equal => a.cmp(&b),
                 _ => ord,
-            })
+            },
+        )
     }
 }