fix typo in array_transform docs

Author: gstvg

datafusion/functions-nested/src/array_transform.rs

@@ -39,13 +39,13 @@ make_udhof_expr_and_func!(
     ArrayTransform,
     array_transform,
     array lambda,
-    "transforms the values of a array",
+    "transforms the values of an array",
     array_transform_udhof
 );
 
 #[user_doc(
     doc_section(label = "Array Functions"),
-    description = "transforms the values of a array",
+    description = "transforms the values of an array",
     syntax_example = "array_transform(array, x -> x*2)",
     sql_example = r#"```sql
 > select array_transform([1, 2, 3, 4, 5], x -> x*2);

docs/source/user-guide/sql/scalar_functions.md

@@ -4379,7 +4379,7 @@ array_to_string(array, delimiter[, null_string])
 
 ### `array_transform`
 
-transforms the values of a array
+transforms the values of an array
 
 ```sql
 array_transform(array, x -> x*2)