title: Angular material datepicker - add content (close button)
body: <p>i am trying to add a button to my angular material datepicker. 
  The button should be added in the top right corner and should close the datepicker on click.</p>
  
  <p>Also i am trying to add additional content inside my datepicker. Since i have disabled dates inside my datepicker i want to add some kind of legend which says that gray dates don't hold any data and therefore can't be selected.</p>
  
  <p>Is there any possibility in adding additional divs or buttons?</p>
  
  <p>Thanks</p>