Fixed README.md typo (#1104)

* Fixed README.md typo

* Fixed example typo

* Fixed example typo

README.md

@@ -1224,7 +1224,7 @@ func main() {
 	if err := srv.Shutdown(ctx); err != nil {
 		log.Fatal("Server Shutdown:", err)
 	}
-	log.Println("Server exist")
+	log.Println("Server exiting")
 }
 ```
 

examples/graceful-shutdown/close/server.go

@@ -41,5 +41,5 @@ func main() {
 		}
 	}
 
-	log.Println("Server exist")
+	log.Println("Server exiting")
 }

examples/graceful-shutdown/graceful-shutdown/server.go

@@ -44,5 +44,5 @@ func main() {
 	if err := srv.Shutdown(ctx); err != nil {
 		log.Fatal("Server Shutdown:", err)
 	}
-	log.Println("Server exist")
+	log.Println("Server exiting")
 }