Indentation fix & Button Listener

Hi Ajay,

I made 2 changes to this so you could see how button click listeners work.

1. I reindented the file so it's a bit easier to read.
2. I moved the button listener to outside of its parent listener, and changed the code to the following:

```javascript
$(document).on('click', 'button', function() {
        $(this).closest('li').remove();
    });
```

This allows you to independently, dynamically listen for buttons and remove the parent li without having to select its parents when searching. Give it a try.