Resolve "Implement basic functionality"

Closes #1 (closed) Closes #2 (closed) Closes #3 (closed) Closes #4 (closed) Closes #5 (closed) Closes #6 (closed)

src/DragContainer.vue

@@ -3,6 +3,8 @@
     <slot>
       <div id="container">
         <dl>
+          <dt>Key</dt>
+          <dd>{{ dragID }}</dd>
           <dt>Position</dt>
           <dd>{{ x }}, {{ y }}</dd>
           <dt>Size</dt>
@@ -18,10 +20,22 @@ export default {
   name: "DragContainer",
   methods: {
     handleDragStart(event) {
-      event.dataTransfer.setData("text", event.target.id);
+      event.dataTransfer.setData(
+          "vueDrag/gridItem",
+          JSON.stringify(
+              {
+                key: this.dragID,
+                x: this.x,
+                y: this.y,
+                w: this.w,
+                h: this.h
+              }
+          )
+      );
     },
   },
   props: {
+    dragID: String,
     x: Number,
     y: Number,
     w: Number,