fixed 795, add community to README

.github/pull_request_template.md

 <!--
-Thank you for contributing to **OceanBase**! Please read the [How to Contribute](https://github.com/oceanbase/oceanbase/wiki/how_to_contribute) document **BEFORE** filing this PR.
+Thank you for contributing to **OceanBase**! Please read the [CONTRIBUTING](https://github.com/oceanbase/oceanbase/blob/master/CONTRIBUTING.md) document **BEFORE** filing this PR.
 -->
 
 ### What changes were proposed in this pull request?

README-CN.md

@@ -77,8 +77,8 @@ OceanBase 数据库使用 [MulanPubL - 2.0](http://license.coscl.org.cn/MulanPub
  - [论坛](https://open.oceanbase.com/answer)
  - [钉钉 33254054](https://h5.dingtalk.com/circle/healthCheckin.html?corpId=ding0e936c01b36c156d60c3ef38bbf6dadc&594d9=30470&cbdbhh=qwertyuiop&origin=1)
  - [微信 oceanbasecommunity](https://gw.alipayobjects.com/zos/oceanbase/0a69627f-8005-4c46-be1f-aac7a2b85c13/image/2022-03-01/85d42796-4e22-463a-9658-57402d7b9bc3.png)
- - [oceanbase.slack](https://oceanbase.slack.com/)
  - Mailist [Comming soon]
+ - Slack [Comming soon]
 
 ## Roadmap
 

README.md

@@ -83,9 +83,8 @@ In case you have any problems when using OceanBase Database, welcome reach out f
  - [Forum](https://open.oceanbase.com/answer)
  - [DingTalk 33254054](https://h5.dingtalk.com/circle/healthCheckin.html?corpId=ding0e936c01b36c156d60c3ef38bbf6dadc&594d9=30470&cbdbhh=qwertyuiop&origin=1)
  - [Wechat oceanbasecommunity](https://gw.alipayobjects.com/zos/oceanbase/0a69627f-8005-4c46-be1f-aac7a2b85c13/image/2022-03-01/85d42796-4e22-463a-9658-57402d7b9bc3.png)
- - [oceanbase.slack](https://oceanbase.slack.com/)
  - Mailist [Comming soon]
- 
+ - Slack [Comming soon]
 
 
 ## Roadmap