Add docker environment setup

[at15]

• install docker
• add doc

[at15]

After following this guide https://www.docker.com/toolbox I can only use docker in the docker quick terminal, while in other terminal, I cant run docker command...

[at15]

and here is how to use it from own shell https://docs.docker.com/installation/mac/#from-your-shell

[at15]

The right guide is

1. follow the guide to install the docker toolbox. It won't conflict with the virtual box you installed using brew cask in TODO:link
2. click the Docker Quickstart Terminal in Application, wait for it to create the vm and then run docker run hello-world to make sure the quickstart terminal is working. Then close this terminal. (This would be mac's default terminal, not iterm, if you didn't configure TODO: how to replace default terminal with iterm
3. open iterm. run docker-machine ls, you should see the default machine created by the quickstart terminal. run docker-machine env default to show the environment config for the default vm.
4. run eval "$(dockermachine env default)" to config current shell, now it is working
5. TODO: add this to your .zshrc or .zsh ? TODO: the guide

[at15]

Still got a problem, after reboot the system, the default vm for docker is not running when start up, so need to run docker-machine start default to start the vm, then open a new tab, and docker command would be avaliable