Fix after review

lib/domain/language_check_service.dart

@@ -5,6 +5,6 @@ abstract class LanguageCheckService {
  /// Creates a new instance of the [LanguageCheckService] class.
  const LanguageCheckService();
 
- /// Function that finds mistakes in given text.
+ /// Returns found mistakes in the given [text].
  Future<List<Mistake>> findMistakes(String text);
 }

lib/domain/mistake.dart

@@ -1,18 +1,18 @@
-/// A data model classs that stores information about a single writing mistake.
+/// A data model class that stores information about a single writing mistake.
 class Mistake {
  /// A brief description of the mistake.
  final String message;
 
  /// A type of this mistake.
  final String type;
 
- /// A position of the beginning of the mistake.
+ /// A position of the beginning of this mistake.
  final int offset;
 
- /// Length of the mistake after the offset.
+ /// Length of this mistake after the offset.
  final int length;
 
- /// A list of suggestions for replacing the mistake.
+ /// A list of suggestions for replacing this mistake.
  ///
  /// Sorted by probability.
  final List<String> replacements;