Added insertion sort algorithm in js and updated README (#37)

* Added insertion sort algorithm in javascript

* listed sorting algorithm in javascript in README.md

sorting/README.md

@@ -26,4 +26,6 @@
 ### JavaScript
 
 1. [Bubble Sort](js/bubble-sort.js)
+2. [Insertion Sort](js/insertion-sort.js)
+3. [Selection Sort](js/selection-sort.js)
 

sorting/js/insertion-sort.js

@@ -0,0 +1,13 @@
+let sort = [12,6,3,88,1,4,8];
+
+for(let i = 0; i<sort.length; i++){
+    let key = sort[i];
+    let j = i-1;
+    //comparing keys with other elements
+    while(key<sort[j] && j>=0){
+        sort[j+1]=sort[j];
+        j--;
+    }
+    sort[j+1]=key;
+}
+console.log(sort)