fix offset

lib/src/widgets/raw_editor.dart

@@ -1,5 +1,6 @@
 import 'dart:async';
 import 'dart:convert';
+import 'dart:math' as math;
 
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/foundation.dart';
@@ -589,7 +590,7 @@ class RawEditorState extends EditorState
 
         if (offset != null) {
           _scrollController.animateTo(
-            offset,
+            math.min(offset, _scrollController.position.maxScrollExtent),
             duration: const Duration(milliseconds: 100),
             curve: Curves.fastOutSlowIn,
           );