Update document_viewer_screen.dart

Author: ZoranJeremic

lib/ui/screens/document_viewer_screen.dart

@@ -1,15 +1,7 @@
-//  f.Sentence - More than text editor.
-    Copyright (C) 2026  Zoran Jeremić
-//  This program is free software: you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-//  This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-//  You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//  f.Sentence - More than text editor. Copyright (C) 2026  Zoran Jeremić
+//  This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
+//  This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+//  You should have received a copy of the GNU General Public License along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 import 'dart:convert';
 import 'package:flutter/material.dart';