Fix alignment

Author: EduardAkhmetshin

arrow-row/src/lib.rs

@@ -432,7 +432,7 @@ mod variable;
 /// "abc"                     ┌──┬────────────────────────────────┐
 ///                           │01│02│'a'│'b'│'c'│00│00│00│00│00│03│
 ///                           └──┴────────────────────────────────┘
-///                            │  └──── string encoding (non-null)
+///                            │  └─ string encoding (non-null)
 ///                            └──── type_id
 ///
 /// null Int32                ┌──┬──────────────┐