docs(searching) correct grammar

subjects/searching/README.md

@@ -2,14 +2,8 @@
 
 ### Instructions
 
-In this exercise you will have to complete the function `search`.
-This **function** receives an array and a key of `i32`, then it will return the position
-of the given key in the array.
-Only arrays with uniques keys will be tested.
-
-### Notions
-
-- [patterns](https://doc.rust-lang.org/book/ch18-00-patterns.html)
+Complete the function `search`. It should return the index of the element which matches `key` in the array.
+> Only arrays with unique elements will be tested.
 
 ### Expected functions
 
@@ -43,3 +37,7 @@ $ cargo run
 the element 6 is in the position Some(3) in the array [1, 3, 4, 6, 8, 9, 11]
 $
 ```
+
+### Notions
+
+- [patterns](https://doc.rust-lang.org/book/ch18-00-patterns.html)