Add component:drag in docs

src/editor/index.js

@@ -32,6 +32,9 @@
  * * `component:toggled` - Component selection changed, toggled model is passed as an argument to the callback
  * * `component:type:add` - New component type added, the new type is passed as an argument to the callback
  * * `component:type:update` - Component type updated, the updated type is passed as an argument to the callback
+ * * `component:drag:start` - Component drag started. Passed an object, to the callback, containing the `target` (component to drag), `parent` (parent of the component) and `index` (component index in the parent)
+ * * `component:drag` - During component drag. Passed the same object as in `component:drag:start` event, but in this case, `parent` and `index` are updated by the current pointer
+ * * `component:drag:end` - Component drag ended. Passed the same object as in `component:drag:start` event, but in this case, `parent` and `index` are updated by the final pointer
  * ### Blocks
  * * `block:add` - New block added
  * * `block:remove` - Block removed