Add ES6 Examples to all chapters (#38)

* add ES6 example for binary search

* add ES6 example for selection sort

* add ES6 example for countdown

* add ES6 example for greet

* add ES6 example for factorial

* edit ES6 example for quicksort

* add ES6 example for loop sum

* add ES6 example for recursive sum

* add ES6 example for recursive count

* add ES6 example for recursive max

* add ES6 example for price of groceries

* add ES6 example for check voter

* add ES6 example for breadth-first search

* add ES6 example for dijkstras algorithm

* edit ES6 example for dijkstras algorithm

* edit ES6 example for set covering

* add ES6 example for longest common subsequence

02_selection_sort/ES6/01_selection_sort.js

@@ -0,0 +1,26 @@
+// Finds the smallest value in an array
+const findSmallest = (arr) => {
+  let smallest = arr[0]; // Stores the smallest value
+  let smallestIndex = 0; // Stores the index of the smallest value
+  for (let i = 1; i < arr.length; i += 1) {
+    if (arr[i] < smallest) {
+      smallest = arr[i];
+      smallestIndex = i;
+    }
+  }
+  return smallestIndex;
+};
+
+// Sort array
+const selectionSort = (arr) => {
+  const newArr = [];
+  const length = arr.length;
+  for (let i = 0; i < length; i += 1) {
+    // Finds the smallest element in the array and adds it to the new array
+    const smallest = findSmallest(arr);
+    newArr.push(arr.splice(smallest, 1)[0]);
+  }
+  return newArr;
+};
+
+console.log(selectionSort([5, 3, 6, 2, 10])); // [2, 3, 5, 6, 10]