Fix wrong describe type on EditorConfig dragMode (#4505)

config dragMode describe would be 'translate' | 'absolute' and not boolean.
it cause wrong alert when use typescript.

Co-authored-by: Artur Arseniev <artur.catch@hotmail.it>

index.d.ts

@@ -175,7 +175,7 @@ declare namespace grapesjs {
      * 'absolute' - Move components absolutely (design tools way)
      * 'translate' - Use translate CSS from transform property
      * To get more about this feature read: https://github.com/artf/grapesjs/issues/1936 */
-    dragMode?: boolean;
+    dragMode?: 'translate' | 'absolute';
 
     /** When the editor is placed in a scrollable container (eg. modals) this might
      * cause elements inside the canvas (eg. floating toolbars) to be misaligned.