Merge pull request #1185 from CreativeCactus/patch-1

Replace %v with %w for error
diff --git a/README.md b/README.md
index 5796706..5152b6a 100644
--- a/README.md
+++ b/README.md
@@ -402,7 +402,7 @@
   // source of the official loggers.
   serialized, err := json.Marshal(entry.Data)
     if err != nil {
-      return nil, fmt.Errorf("Failed to marshal fields to JSON, %v", err)
+      return nil, fmt.Errorf("Failed to marshal fields to JSON, %w", err)
     }
   return append(serialized, '\n'), nil
 }