title: how to make buttons float over an image on mouse over in ReactJS
body: <p>I have an image gallery in ReactJS using bootstrap. I want to add buttons to delete or further modify the images. These buttons should only appear in the corner of the image when the mouse is over the respective image.
  I've been looking far and wide and either I just don't know the right terms as to what this is called or it is not as common as I thought.
  Of course if the same question already answered exists I'd be more than thankful to be pointed to said question.</p>