Add README so that package info on pkg.go.dev will be shown more nicely (#11)

* Add README so that package info on pkg.go.dev will be shown more nicely

* Update README.md

Author: pavelflux

README.md

@@ -1,13 +1,38 @@
 # Eppo SDK for Golang
 
-## Building
+Eppoclient is a client sdk for `eppo.cloud` randomization API.
+It is used to retrieve the experiments data and put it to in-memory cache, and then get assignments information.
 
-```
-make build
-```
+## Getting Started
+
+Refer to our [SDK documentation](https://docs.geteppo.com/prerequisites/feature-flagging/randomization-sdk/) for how to install and use the SDK.
+
+## Supported Python Versions
+This version of the SDK is compatible with Python 3.6 and above.
+
+## Example
 
-## Running tests
 
 ```
-make test
+	import (
+		"github.com/Eppo-exp/golang-sdk/eppoclient"
+	)
+
+	var eppoClient = &eppoclient.EppoClient{}
+
+	func main() {
+		eppoClient = eppoclient.InitClient(eppoclient.Config{
+			ApiKey:           "<your_api_key>",
+			BaseUrl:          "<base_url>", // optional, default https://eppo.cloud/api
+			AssignmentLogger: eppoclient.AssignmentLogger{},
+		})
+	}
+
+	func someBLFunc() {
+		assignment, _ := eppoClient.GetAssignment("subject-1", "experiment_5", sbjAttrs)
+
+		if assigment == "control" {
+			// do something
+		}
+	}
 ```