polish

README.md

@@ -90,7 +90,7 @@ Drop TABLE `demo`
 Thrive together in Apache HoraeDB community with users and developers from all around the world.
 
 - Discuss at [dev mailing list](mailto:dev-subscribe@horaedb.apache.org) ([subscribe](mailto:dev-subscribe@horaedb.apache.org?subject=(send%20this%20email%20to%20subscribe)) / [unsubscribe](mailto:dev-unsubscribe@horaedb.apache.org?subject=(send%20this%20email%20to%20unsubscribe)) / [archives](https://lists.apache.org/list.html?dev@horaedb.apache.org))
-- Send [request](mailto:dev@horaedb.apache.org?subject=(Request%to%20join%20HoraeDB%20slack)) to `dev@horaedb.apache.org` to join HoraeDB slack channel.
+- Send [request](mailto:dev@horaedb.apache.org?subject=(Request%to%20join%20HoraeDB%20slack)) to `dev@horaedb.apache.org` to join HoraeDB slack channel
 - Or you can join our [dingtalk group](https://github.com/apache/incubator-horaedb-docs/blob/main/static/dingtalk.jpg)
 
 Read our [Contributing Guide](CONTRIBUTING.md) and make your first contribution!