Update readme with example

Author: aaronvb

README.md

@@ -1,5 +1,5 @@
 # aaronvb/logrequest
-Package `aaronvb/logrequest` is a Go middleware log output inspired by the Ruby on Rails log out for requests. Example output:
+Package `aaronvb/logrequest` is a Go middleware log output inspired by the Ruby on Rails log output for requests. Example output:
 
 ```sh
 Started GET "/" 127.0.0.1:12345 HTTP/1.1
@@ -11,4 +11,87 @@ The output can directly sent to `log.Logger` or to a map[string]string with the
 ## Install
 ```sh
 go get -u github.com/aaronvb/logrequest
-```
+```
+
+## Middleware Example (using [gorilla/mux](https://github.com/gorilla/mux))
+```go
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"time"
+
+	"github.com/aaronvb/logrequest"
+
+	"github.com/gorilla/mux"
+)
+
+type application struct {
+	errorLog *log.Logger
+	infoLog  *log.Logger
+}
+
+func main() {
+	infoLog := log.New(os.Stdout, "INFO\t", log.Ldate|log.Ltime)
+	errorLog := log.New(os.Stderr, "ERROR\t", log.Ldate|log.Ltime|log.Lshortfile)
+
+	app := &application{
+		errorLog: errorLog,
+		infoLog:  infoLog,
+	}
+
+	srv := &http.Server{
+		Addr:     ":8080",
+		ErrorLog: errorLog,
+		Handler:  app.routes(),
+	}
+
+	infoLog.Printf("Starting server on %s", ":8080")
+	err := srv.ListenAndServe()
+	errorLog.Fatal(err)
+}
+
+func (app *application) routes() http.Handler {
+	r := mux.NewRouter()
+	r.HandleFunc("/foobar", app.foobar).Methods("GET")
+
+	// Middleware
+	r.Use(app.logRequest)
+
+	return r
+}
+
+func (app *application) foobar(w http.ResponseWriter, r *http.Request) {
+	time.Sleep(300 * time.Millisecond)
+	fmt.Fprintln(w, "Hello world")
+}
+
+// Middleware
+
+func (app *application) logRequest(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		lr := logrequest.LogRequest{Request: r, Writer: w, Handler: next}
+		lr.ToLogger(app.infoLog)
+	})
+}
+```
+
+```sh
+> go run main.go
+INFO	2020/03/31 22:40:09 Starting server on :8080
+INFO	2020/03/31 22:40:13 Started GET "/foobar" [::1]:55044 HTTP/1.1
+INFO	2020/03/31 22:40:13 Completed 200 in 300.131639ms
+INFO	2020/03/31 22:40:18 Started GET "/foobar" [::1]:55044 HTTP/1.1
+INFO	2020/03/31 22:40:18 Completed 200 in 302.047625ms
+```
+
+## Showing Parameters
+```sh
+INFO	2020/03/31 22:40:13 Started GET "/foobar" [::1]:55044 HTTP/1.1
+INFO	2020/03/31 22:40:13 Parameters: {"foo" => "bar"}
+INFO	2020/03/31 22:40:13 Completed 200 in 300.131639ms
+```
+Check out my other middleware package to output incoming parameters, which is also influenced by the Ruby on Rails logger:  [https://github.com/aaronvb/logparams](https://github.com/aaronvb/logparams)