doc: add example on readme

Signed-off-by: Nugraha <richiisei@gmail.com>

README.md

@@ -1 +1,46 @@
-# gouring
+# gouring
+
+[![License: MIT][1]](LICENSE)
+[![Go Reference][2]][3]
+
+
+```bash
+go get github.com/ii64/gouring
+```
+## Example
+
+```go
+// setup
+h, err := gouring.New(256, 0)
+if err != nil { /*...*/ }
+defer h.Close() 
+
+sqe := h.GetSQE()
+b := []byte("io_uring!\n")
+PrepWrite(sqe, 1, &b[0], len(b), 0)
+
+submitted, err := h.SubmitAndWait(1)
+if err != nil { /*...*/ }
+println(submitted) // 1
+
+var cqe *gouring.IoUringCqe
+err = h.WaitCqe(&cqe) 
+if err != nil { /*...*/ } // check also EINTR
+
+_ = cqe.UserData
+_ = cqe.Res
+_ = cqe.Flags
+```
+
+## Graph
+
+_placeholder_
+
+### Reference
+
+https://github.com/axboe/liburing
+
+
+[1]: https://img.shields.io/badge/License-MIT-yellow.svg
+[2]: https://pkg.go.dev/badge/github.com/ii64/gouring.svg
+[3]: https://pkg.go.dev/github.com/ii64/gouring