Install xubuntu 18.04

readme.txt

1. vscode from https://code.visualstudio.com/
2. ruby 2.6.5 from https://www.ruby-lang.org/zh_cn/, add bin path to /etc/environment
3. nodejs from https://nodejs.org/zh-cn/, sudo tar xf xx.tar.gz -C /usr/local, and add bin path to /etc/environment
4. sudo visudo, Add ruby and node path to secret path.
5. sudo npm install -g yarn
6. curl, git, gitg
    $ git config --global user.name "qichunren"
    $ git config --global user.email [email protected]
7. openssh-server
8. Set up ssh key with right permisson flag.