docs: add zerolog example

Signed-off-by: Bo-Yi Wu <[email protected]>

Author: appleboy

README.md

@@ -1,3 +1,64 @@
 # contrib
 
 [![Run Tests](https://github.com/golang-queue/contrib/actions/workflows/go.yml/badge.svg)](https://github.com/golang-queue/contrib/actions/workflows/go.yml)
+
+## Logger Interface
+
+```go
+type Logger interface {
+  Infof(format string, args ...interface{})
+  Errorf(format string, args ...interface{})
+  Fatalf(format string, args ...interface{})
+  Info(args ...interface{})
+  Error(args ...interface{})
+  Fatal(args ...interface{})
+}
+```
+
+* [x] zerolog
+
+## Example
+
+zerolog
+
+```go
+package main
+
+import (
+  "context"
+  "fmt"
+  "time"
+
+  "github.com/golang-queue/contrib/zerolog"
+  "github.com/golang-queue/queue"
+)
+
+func main() {
+  taskN := 100
+  rets := make(chan string, taskN)
+
+  // initial queue pool
+  q := queue.NewPool(5, queue.WithLogger(zerolog.New()))
+  // shutdown the service and notify all the worker
+  // wait all jobs are complete.
+  defer q.Release()
+
+  // assign tasks in queue
+  for i := 0; i < taskN; i++ {
+    go func(i int) {
+      if err := q.QueueTask(func(ctx context.Context) error {
+        rets <- fmt.Sprintf("Hi Gopher, handle the job: %02d", +i)
+        return nil
+      }); err != nil {
+        panic(err)
+      }
+    }(i)
+  }
+
+  // wait until all tasks done
+  for i := 0; i < taskN; i++ {
+    fmt.Println("message:", <-rets)
+    time.Sleep(20 * time.Millisecond)
+  }
+}
+```