Fix inability to find mistake in the next lines

lib/client/language_tool_client.dart

@@ -8,6 +8,10 @@ import 'package:languagetool_textfield/domain/writing_mistake.dart';
 ///
 /// Read more @ https://languagetool.org/http-api/swagger-ui/#/
 class LanguageToolClient {
+  /// A language code like en-US, de-DE, fr, 
+  /// or auto to guess the language automatically 
+  final String language;
+
   /// Url of LanguageTool API.
   static const _url = 'api.languagetoolplus.com';
 
@@ -18,20 +22,14 @@ class LanguageToolClient {
   };
 
   /// Constructor for [LanguageToolClient].
-  LanguageToolClient();
+  LanguageToolClient({this.language = 'auto'});
 
   /// Checks the errors in text.
-  Future<List<WritingMistake>> check(
-    String text, {
-    String language = 'auto',
-  }) async {
-    final encodedText = Uri.encodeQueryComponent(text);
-    final encodedLanguage = Uri.encodeQueryComponent(language);
-
+  Future<List<WritingMistake>> check(String text) async {
     final result = await http.post(
       Uri.https(_url, 'v2/check', {
-        'text': encodedText,
-        'language': encodedLanguage,
+        'text': text,
+        'language': language,
         'enabledOnly': 'false',
         'level': 'default',
       }),