docs: update file interface with field description

src/backend/utils/uploaded-file.type.ts

@@ -1,11 +1,27 @@
 /**
  * File uploaded via FormData to the backend.
  *
- * @memberof adminbro
+ * @memberof AdminBro
+ * @alias UploadedFile
  */
 export type UploadedFile = {
+  /**
+   * The size of the uploaded file in bytes.
+   * this property says how many bytes of the file have been written to disk yet.
+   */
   size: number;
+  /**
+   * The path this file is being written to.
+   */
   path: string;
+
+  /**
+   * The mime type of this file, according to the uploading client.
+   */
   type: string;
-  name: string;
+
+  /**
+   * The name this file had according to the uploading client.
+   */
+  name: string | null;
 }