* Improve README.md

Author: zulffaza

README.md

@@ -1,9 +1,65 @@
 # Seller API Client for Java
 
+<hr>
+
 It's an initial Java project to connect to Blibli Seller API. 
 Please feel free to relay your comments, suggestions or corrections through pull request.
 
-Installation step:
-1. Download/clone the initial project
-2. Look at 'App.java' as a main class. It show you to use the client's code
-3. Or download the final .jar here https://github.com/bliblidotcom/seller-api-client-java/releases/tag/1.0.0-1
+### Setup
+
+<hr>
+
+##### Maven
+
+```xml
+<!-- Add seller api client dependency -->
+<dependency>
+    <groupId>com.blibli.oss.sellerapi.client</groupId>
+    <artifactId>seller-api-client</artifactId>
+    <version>${seller-api-client.version}</version>
+</dependency>
+
+<!-- Set seller api client version -->
+<properties>
+    <seller-api-client.version>...</seller-api-client.version>
+</properties>
+
+<!-- add blibli bintray repository --> 
+<repositories>
+    <repository>
+      <snapshots>
+        <enabled>false</enabled>
+      </snapshots>
+      <id>bintray-bliblidotcom-maven</id>
+      <name>bintray</name>
+      <url>https://dl.bintray.com/bliblidotcom/maven</url>
+    </repository>
+</repositories>
+```
+
+##### JAR
+
+> [Release note](https://github.com/bliblidotcom/seller-api-client-java/releases)
+
+- v1.2.0-1 : https://github.com/bliblidotcom/seller-api-client-java/releases/tag/1.2.0-1
+- v1.1.0-1 : https://github.com/bliblidotcom/seller-api-client-java/releases/tag/1.1.0-1
+
+### Code Sample
+
+<hr>
+
+##### OAuth Flow
+
+> Run App.java
+
+1. Send token request to `https://api-uata.gdn-app.com/v2/oauth/token`
+2. Send refresh token request with `[1]` response to `https://api-uata.gdn-app.com/v2/oauth/token`
+3. Send order detail request with access token from `[2]` to `https://api-uata.gdn-app.com/v2/proxy/mta/api/businesspartner/v1/order/orderDetail`
+4. Send fulfill order request with package id from `[3]` to `https://api-uata.gdn-app.com/v2/proxy/seller/v1/orders/regular/{packageId}/fulfill`
+
+##### Basic Auth Flow
+
+> Run AppBasicAuth.java
+
+1. Send order detail request to `https://api-uata.gdn-app.com/v2/proxy/mta/api/businesspartner/v1/order/orderDetail`
+2. Send fulfill order request with package id from `[1]` to `https://api-uata.gdn-app.com/v2/proxy/seller/v1/orders/regular/{packageId}/fulfill`