Resolve "Implement basic functionality"

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

src/DragGrid.vue

@@ -21,7 +21,7 @@
       :context="context"
       :grid-id="gridId"
     >
-      <slot v-bind="transformItem(item)" name="item">
+      <slot v-bind="transformItem(item)" :raw-item="item" name="item">
         <dl>
           <dt>Key</dt>
           <dd>{{ item.key }}</dd>
@@ -189,6 +189,7 @@ export default {
 
       element.x = coords.x;
       element.y = coords.y;
+      element.gridId = this.gridId;
       this.$emit("itemChanged", element);
     },
     getCoords(x, y) {