Add Contact API (#340)

* feat: add basic files of contact

* chore: code review
1. delete redundant suffix
2. use tab replace whitespace in pb file

* chore: add some comments and check post data validation

* chore: add some comments

* chore: add publicapi.json and examples.json

* chore: update README.md

* fix: code review conversations

contact/main.go

@@ -0,0 +1,30 @@
+package main
+
+import (
+	"github.com/micro/micro/v3/service/store"
+
+	"github.com/micro/services/contact/domain"
+	"github.com/micro/services/contact/handler"
+	pb "github.com/micro/services/contact/proto"
+
+	"github.com/micro/micro/v3/service"
+	"github.com/micro/micro/v3/service/logger"
+)
+
+func main() {
+	// Create service
+	srv := service.New(
+		service.Name("contact"),
+		service.Version("latest"),
+	)
+
+	contactDomain := domain.NewContactDomain(store.DefaultStore)
+
+	// Register handler
+	pb.RegisterContactHandler(srv.Server(), handler.NewContact(contactDomain))
+
+	// Run service
+	if err := srv.Run(); err != nil {
+		logger.Fatal(err)
+	}
+}