matcher: fixed status file, formatting, tweaks to readme

lib/src/interfaces.dart

Index: lib/src/interfaces.dart
diff --git a/lib/src/interfaces.dart b/lib/src/interfaces.dart
index f3f0755c6a1c4e91df8f5bf77f140d44f434d4b3..984d8628d3dda180051a151c14036db14e50de03 100644
--- a/lib/src/interfaces.dart
+++ b/lib/src/interfaces.dart
@@ -54,6 +54,7 @@ abstract class Matcher {
   /// A few matchers make use of the [verbose] flag to provide detailed
   /// information that is not typically included but can be of help in
   /// diagnosing failures, such as stack traces.
-  Description describeMismatch(item, Description mismatchDescription,
-      Map matchState, bool verbose) => mismatchDescription;
+  Description describeMismatch(
+      item, Description mismatchDescription, Map matchState, bool verbose) =>
+      mismatchDescription;
 }