feat(JS): correct typo

Author: josueJURE

index.js

@@ -191,7 +191,7 @@ function userClicksOnEqualButton(button) {
         screen.innerText = "0÷0 is an invalid format. Press AC";
       } else {
         let result = eval(replacedArray.join(""));
-        let historyEntries = [[...replacedArray, "=", result]]; // Used slice() at firest. But slice() is not sufficient because it only creates a shallow copy of the array, and modifications to the new array will still affect the original array. The spread syntax ([...replacedArray]), which creates a shallow copy as well, is a concise way to create a new array with the same elements as the existing array. While ensuring that modifications to historyEntries do not affect replacedArray, and vice versa.
+        let historyEntries = [[...replacedArray, "=", result]]; // Used slice() at first. But slice() is not sufficient because it only creates a shallow copy of the array, and modifications to the new array will still affect the original array. The spread syntax ([...replacedArray]), which creates a shallow copy as well, is a concise way to create a new array with the same elements as the existing array. While ensuring that modifications to historyEntries do not affect replacedArray, and vice versa.
         replacedArray.splice(replacedArray.length, 0, "=", result);
         displayResult(replacedArray, result);
         screen.innerText = !Number.isFinite(result)