add readme

Signed-off-by: Artashes Balabekyan <balabekyanartashes@gmail.com>

README.md

@@ -0,0 +1,60 @@
+# The OpenStack Barbican SDK fo Golang
+
+## Usage
+
+```go
+import (
+	"context"
+	"fmt"
+
+	barbican "github.com/artashesbalabekyan/barbican-sdk-go"
+	"github.com/artashesbalabekyan/barbican-sdk-go/xhttp"
+)
+
+func main() {
+	ctx := context.Background()
+
+	config := &xhttp.Config{
+		Endpoint: "https://<endpoint>",
+		Login: xhttp.Credentials{
+			ProjectDomain:  "default",
+			ProjectName:    "<project_name>",
+			AuthUrl:        "https://<auth_url>",
+			Username:       "<userName>",
+			Password:       "<password>",
+			UserDomainName: "Default",
+		},
+	}
+
+	client, err := barbican.NewConnection(ctx, config)
+	if err != nil {
+		panic(err)
+	}
+}
+
+```
+
+```go
+err := client.Create(ctx, "my-key", []byte("my-value"))
+if err != nil {
+    panic(err)
+}
+
+```
+
+```go
+iterator, err := client.ListSecrets(ctx)
+if err != nil {
+    panic(err)
+}
+
+defer iterator.Close()
+
+for {
+    name, ok := iterator.Next()
+    if !ok {
+        break
+    }
+    fmt.Println(name)
+}
+```