When clicking on kanban box, the first action is trigger; the user have to click on the label of the box to see the 'timesheet' (for instance), otherwise he will see the tasks. Since HTML5 supports `div`, `table`, ... being wrapped by `a` tag, we can use it to make the entire kanban box clickable. (See https://www.w3.org/TR/html5/text-level-semantics.html#the-a-element)