docker documentation for config files is no longer valid

The docker installation instructions (https://github.com/solid/node-solid-server#use-docker) have a step:

docker cp solid:/usr/src/app/config.json .

However by default this file doesn't exist, I get an error:

Error: No such container:path: solid:/usr/src/app/config.json

I was able to successfully create a config file using solid init and then copy it

perhaps these instructions need to be updated to cover some recent changes to the docker setup?

从链接的“use-docker”部分中的 Docker 安装说明开始，将文档记录的 docker cp 步骤与 issue 中描述的行为进行比较。检查 solid init 如何在 Docker 设置中创建配置文件。当这些说明能够在全新安装上正确生成或找到配置文件时，即表示完成。