extract and cleanup some functions

types/index.d.ts

@@ -21,6 +21,7 @@ export type OdFolderObject = {
     thumbnails?: Array<OdThumbnail>
   }>
 }
+export type OdFolderChildren = OdFolderObject['value'][number]
 // A file object returned from the OneDrive API. This object may contain 'video' if the file is a video.
 export type OdFileObject = {
   '@microsoft.graph.downloadUrl': string