HugeGraph-1358: update readme for release-0.12 (#1717)

Change-Id: I3e71ec79e926d0ba09aa6dc4bcb596ff71c15390

Author: javeme

README.md

@@ -1,9 +1,9 @@
 # HugeGraph
 
 [![License](https://img.shields.io/badge/license-Apache%202-0E78BA.svg)](https://www.apache.org/licenses/LICENSE-2.0.html)
-[![Build Status](https://github.com/hugegraph/hugegraph/actions/workflows/ci.yml/badge.svg)](https://github.com/hugegraph/hugegraph/actions/workflows/ci.yml)
-[![Codecov](https://codecov.io/gh/hugegraph/hugegraph/branch/master/graph/badge.svg)](https://codecov.io/gh/hugegraph/hugegraph)
-[![Github Releases Downloads](https://img.shields.io/github/downloads/hugegraph/hugegraph/total.svg)](https://github.com/hugegraph/hugegraph/releases)
+[![Build Status](https://github.com/hugegraph/hugegraph/actions/workflows/ci.yml/badge.svg?branch=release-0.12)](https://github.com/hugegraph/hugegraph/actions/workflows/ci.yml)
+[![Codecov](https://codecov.io/gh/hugegraph/hugegraph/branch/release-0.12/graph/badge.svg)](https://codecov.io/gh/hugegraph/hugegraph)
+[![Github Releases Downloads](https://img.shields.io/github/downloads/hugegraph/hugegraph/v0.12.0/total.svg)](https://github.com/hugegraph/hugegraph/releases)
 
 HugeGraph is a fast-speed and highly-scalable [graph database](https://en.wikipedia.org/wiki/Graph_database). Billions of vertices and edges can be easily stored into and queried from HugeGraph due to its excellent OLTP ability. As compliance to [Apache TinkerPop 3](https://tinkerpop.apache.org/) framework, various complicated graph queries can be accomplished through [Gremlin](https://tinkerpop.apache.org/gremlin.html)(a powerful graph traversal language).