add notice for docker run gitea http port issue (#3020)

Author: lunny

docs/content/doc/installation/with-docker.en-us.md

@@ -183,6 +183,8 @@ To start this setup based on `docker-compose` you just have to execute `docker-c
 
 If you want to shutdown the setup again just execute `docker-compose down`, this will stop and kill the containers, the volumes will still exist.
 
+Notice: if you use a non 3000 port on http, you need change app.ini `LOCAL_ROOT_URL  = http://localhost:3000/`.
+
 ## Install
 
 After starting the Docker setup via `docker-compose` you should access Gitea with your favorite browser to finalize the installation. Please visit http://server-ip:3000 and follow the installation wizard. If you have started a database with the `docker-compose` setup as documented above please note that you have to use `db` as the database hostname.

docs/content/doc/installation/with-docker.zh-cn.md

@@ -37,6 +37,8 @@ docker run -d --name=gitea -p 10022:22 -p 10080:3000 -v /var/lib/gitea:/data git
 
 然后 容器已经运行成功，在浏览器中访问 http://hostname:10080 就可以看到界面了。你可以尝试在上面创建项目，clone操作 `git clone ssh://git@hostname:10022/username/repo.git`.
 
+注意：目前端口改为非3000时，需要修改配置文件 `LOCAL_ROOT_URL  = http://localhost:3000/`。
+
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