chore: add badges and update supported features in README.md (#9)

diff --git a/README.md b/README.md
index c96c64f..0a8ebf4 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,9 @@
 # CeresDB Python Client
 
 ![License](https://img.shields.io/badge/license-Apache--2.0-green.svg)
+[![CI](https://github.com/CeresDB/ceresdb-client-py/actions/workflows/ci.yml/badge.svg)](https://github.com/CeresDB/ceresdb-client-py/actions/workflows/ci.yml)
+[![OpenIssue](https://img.shields.io/github/issues/CeresDB/ceresdb-client-py)](https://github.com/CeresDB/ceresdb-client-py/issues)
+[![Slack](https://badgen.net/badge/Slack/Join%20CeresDB/0abd59?icon=slack)](https://join.slack.com/t/ceresdbcommunity/shared_invite/zt-1au1ihbdy-5huC9J9s2462yBMIWmerTw)
 
 ## Introduction
 The python client for CeresDB.
@@ -8,7 +11,7 @@
 
 ## Support features
 - [x] Query
-- [ ] Write
+- [x] Write
 
 ## Contributing
 Any contribution is welcome!