Update README.md (dart-archive/lints#108)

Author: mit-mit

pkgs/lints/README.md

@@ -9,7 +9,7 @@ Dart source code. More than a hundred [linter rules][rules] are available,
 checking anything from potential typing issues, coding style, and formatting.
 This package, `lints`, contains the lint settings recommended by the Dart team.
 
-Two sets of lints are available:
+Two sets of Dart lints are available:
 
 * **Core lints**: Lints that help identify critical issues that are likely to
 lead to problems when running or consuming Dart code. All code should pass these
@@ -20,6 +20,9 @@ lead to problems when running or consuming Dart code, and lints that enforce
 writing Dart using a single, idiomatic style and format. All code is encouraged
 to pass these lints. The recommended lints include all the core lints.
 
+Finally, a third set [`flutter_lints`](https://pub.dev/packages/flutter_lints)
+extends the recommended set with additional recommencded Flutter-specific lints.
+
 ## Where these lints are used
 
 When creating new Dart project using the [`dart create`][dart create] command,