standardised util functions comments (#1805)

* standardised util functions comments

* Update pixelSetter.js

* Update pixelSetter.js

* Update pixelSetter.js

Co-authored-by: Harsh Khandeparkar <34770591+HarshKhandeparkar@users.noreply.github.com>

src/util/getDefaults.js

@@ -1,3 +1,4 @@
+/** Parses the defaults and gets the input which is available. */
 module.exports = function(info){
   var defaults = {};
   for (var key in info.inputs) {

src/util/pixelSetter.js

@@ -1,5 +1,12 @@
+/**  
+ * @param {number} x x-coordinate.
+ * @param {number} y y-coordinate.
+ * @param {object} value array [r, g, b, a]
+ * @param {object} pixels NDarray of pixels.
+ * @description Sets the pixels from 0 through length of value. 
+*/
 module.exports = function(x, y, value, pixels){
   for(let i = 0; i < value.length; i++){
     pixels.set(x, y, i, value[i]);
   }
-};
+};