Put the whole thing on one line like this:
var anotherListItem = '<div class="form-list"><button class="done"></button><input type="text"></div>';
For multiple lines, you'd have to use string concatenation:
var anotherListItem2 = '<div class="form-list">'+
'<button class="done"></button>'+
'<input type="text">'+
'</div>'
Remember, if you want to bind a click handler or similar to a dynamically added element, you have to use Event Delegation
Below is a contrived example:
$('#container').on('click','.done', function(){
alert('this works');
});
var anotherListItem = '<div class="form-list"><button class="done">press me</button><input type="text"></div>';
$('#container').append( anotherListItem );
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js"></script>
<div id="container"></div>