升级容器 - 保留配置和数据

[md-misko]

@tschloss

Q: how to upgrade an existing installation through Docker?

Manually update Discourse and Docker image to latest

If you self-host Discourse, you occasionally need to run a manual update via the command line to get the latest security releases newest libraries. These updates are not picked up in admin/update, which is why you’ll occasionally need to do this additional step. Discourse itself should be updated about twice a month, by clicking the “Update to Latest Version” button in your admin dashboard (admin/update). Every two months we recommend SSH’ing into your web server (using putty or your favor…