chore: fix super minor lint issues

Author: EchoEllet

lib/src/editor/config/editor_config.dart

@@ -1,4 +1,4 @@
-/// @docImport '../../rules/insert.dart' show AutoFormatMultipleLinksRule;
+/// @docImport '../../rules/insert.dart';
 library;
 
 import 'dart:ui' as ui;

lib/src/rules/format.dart

@@ -133,8 +133,8 @@ class FormatLinkAtCaretPositionRule extends FormatRule {
     final delta = Delta();
     final itr = DeltaIterator(document.toDelta());
     final before = itr.skip(index), after = itr.next();
-    int beg = index;
-    int retain = 0;
+    var beg = index;
+    var retain = 0;
     if (before != null && before.hasAttribute(attribute.key)) {
       beg -= before.length!;
       retain = before.length!;

lib/src/toolbar/config/buttons/link_style_options.dart

@@ -1,4 +1,4 @@
-/// @docImport '../../../rules/insert.dart' show AutoFormatMultipleLinksRule;
+/// @docImport '../../../rules/insert.dart';
 library;
 
 import '../../../common/utils/link_validator.dart';