chore: Add doc comment

packages/altive_lints/lib/src/lints/avoid_hardcoded_japanese.dart

@@ -1,6 +1,28 @@
 import 'package:analyzer/error/listener.dart';
 import 'package:custom_lint_builder/custom_lint_builder.dart';
 
+/// An `avoid_hardcoded_japanese` rule which detects
+/// and reports hardcoded Japanese text strings within the code.
+///
+/// This rule ensures that all user-facing text is
+/// properly internationalized to support Japanese localization efforts.
+///
+/// ### Example
+///
+/// #### BAD:
+///
+/// ```dart
+/// final message = 'こんにちは'; // LINT
+/// print('エラーが発生しました'); // LINT
+/// ```
+///
+/// #### GOOD:
+///
+/// ```dart
+/// final message = AppLocalizations.of(context).hello;
+/// print(AppLocalizations.of(context).errorOccurred);
+/// ```
+///
 class AvoidHardcodedJapanese extends DartLintRule {
   const AvoidHardcodedJapanese() : super(code: _code);
 
@@ -35,8 +57,8 @@ class AvoidHardcodedJapanese extends DartLintRule {
     });
   }
 
-  // Checks if the string contains Japanese characters
-  // (Hiragana, Katakana, Kanji).
+  /// Checks if the string contains Japanese characters
+  /// (Hiragana, Katakana, Kanji).
   bool isJapanese(String value) =>
       RegExp(r'[\u3040-\u309F\u30A0-\u30FF\u4E00-\u9FD0]').hasMatch(value);
 }