chore: fix some linting issues

Signed-off-by: Shengqi Chen <harry-chen@outlook.com>

Author: Harry-Chen

lib/ndef.dart

@@ -6,7 +6,7 @@
 /// Use [decodeRawNdefMessage] to decode raw NDEF messages from byte arrays,
 /// [decodePartialNdefMessage] to decode individual records with separate parts,
 /// and [encodeNdefMessage] to encode NDEF messages to byte arrays.
-library ndef;
+library;
 
 import 'dart:typed_data';
 

lib/record.dart

@@ -101,6 +101,7 @@ typedef TypeFactory = NDEFRecord Function(TypeNameFormat tnf, String classType);
 /// The base class of all types of records.
 /// Also represents an record of unknown type.
 class NDEFRecord {
+  /// String representations of the TNF values.
   static const List<String> tnfString = [
     "",
     "urn:nfc:wkt:",