docs(fusion): correct grammar

subjects/fusion/README.md

@@ -2,38 +2,38 @@
 
 ### Instructions
 
-The objective of this exercise is to merge objects into a new object depending on the values type
+The objective of this exercise is to merge objects into a new object depending on the values type.
 
-With this, create a function called `fusion` that:
+Create a function named `fusion` that:
 
-- If the type is an array you must concatenate it
+- For array types, you will concatenate them.
 
 ```js
 fusion({ arr: [1, "2"] }, { arr: [2] }); // -> { arr: [ 1, '2', 2 ] }
 fusion({ arr: [], arr1: [5] },{ arr: [10, 3], arr1: [15, 3], arr2: ["7", "1"] }); // ->{ arr: [ 10, 3 ], arr1: [ 5, 15, 3 ], arr2: [ '7', '1' ] }
 ```
 
-- If it is a string you must concatenate it with a space
+- For strings, you must concatenate them with a space.
 
 ```js
 fusion({ str: "salem" }, { str: "alem" }); // -> { str: 'salem alem' }
 fusion({ str: "salem" }, { str: "" }); // -> { str: 'salem ' }
 ```
 
-- If they are numbers, you must add them
+- If they are numbers, you must add them.
 
 ```js
 fusion({ a: 10, b: 8, c: 1 }, { a: 10, b: 2 }); // -> { a: 20, b: 10, c: 1 }
 ```
 
-- If it is an object, you must join them recursively
+- If it is an object, you must join them recursively.
 
 ```js
 fusion({ a: 1, b: { c: "Salem" } }, { a: 10, x: [], b: { c: "alem" } }); // -> { a: 11, x: [], b: { c: 'Salem alem' } }
 fusion( { a: { b: [3, 2], c: { d: 8 } } },{ a: { b: [0, 3, 1], c: { d: 3 } } }); // -> { a: { b: [ 3, 2, 0, 3, 1 ], c: { d: 11 } } }
 ```
 
-- In case of type mismatch you must replace it with the value of the second object
+- In case of type mismatch you must replace it with the value of the second object (if it exists).
 
 ```js
 fusion({ a: "hello", b: [] }, { a: 4 }); // -> { a: 4, b: [] }