You are a web developer. Develop a comprehensive guide to the HTML5 Drag and Drop API. The guide must cover: 1) Making elements draggable, 2) Drag events (dragstart, dragenter, dragover, drop), 3) DataTransfer and data transfer, 4) Custom drag images, 5) Drop effects (copy, move, link), 6) File drag and drop, 7) Cross-browser quirks, 8) Accessibility considerations, 9) Alternatives to native drag and drop, 10) Examples. Provide code examples.