Include example HTML5 Drag and Drop API

There is a chapter called [“Drag'n'Drop with mouse events”](https://javascript.info/mouse-drag-and-drop), and it makes a passing reference to the Drag and Drop API. There are plenty of cases where it’s appropriate to choose this approach.

However, I think there also needs to be a “Drag'n'Drop with the API” chapter.

I’ve been using the DND API on a learning project. Although I got over the strange hurdle of learning which events apply to draggable items and which events apply to drop zones, I’m at a point where I am really missing the awesome guidance I can find on most other topics in your excellent work.

For the purpose of inspiration in creating such a chapter (or for anyone else reading this), one tutorial I found helpful helpful is this video (which includes the basics of the DND API, and implements a list-sorting feature):

https://www.youtube.com/watch?v=jfYWwQrtzzY

Lesen Sie das bestehende Kapitel „Drag'n'Drop with mouse events“ unter https://javascript.info/mouse-drag-and-drop und sehen Sie sich das referenzierte Tutorialvideo an, um die Abdeckung der HTML5 Drag and Drop API zu prüfen. Als abgeschlossen gilt die Aufgabe, wenn ein neues Kapitel hinzugefügt wurde, das die API erklärt, einschließlich der Ereignisse für draggable-item und drop-zone, und praktische Hinweise dazu gibt, wann sie verwendet werden sollte.

Vom Indexierungsmodell aus dem Issue-Text verfasst.