fix(nodeOperation): prevent incorrect sibling insertion in root node

fixed #329

Author: SSShooter

package.json

@@ -1,6 +1,6 @@
 {
   "name": "mind-elixir",
-  "version": "4.6.1",
+  "version": "4.6.2",
   "type": "module",
   "description": "Mind elixir is a free open source mind map core.",
   "keywords": [

src/nodeOperation.ts

@@ -60,7 +60,7 @@ export const insertSibling = function (this: MindElixirInstance, type: 'before'
   if (!nodeObj.parent) {
     this.addChild()
     return
-  } else if (!nodeObj.parent?.parent && nodeObj.parent?.children?.length === 1) {
+  } else if (!nodeObj.parent?.parent && nodeObj.parent?.children?.length === 1 && this.direction === 2) {
     // add at least one node to another side
     this.addChild(findEle(nodeObj.parent!.id), node)
     return