Install docker

• problem with "can't start docker demon" after using sudo service docker start, use sudo usermod -aG docker <user-id> logout and login again will work
• many nonsense words, why use docker? why start a virtual machine? should I install the required software inside the virtual machine or in the development host? seem like no use...
• it's cool to trace all user's compile/build/debug log.
• feel boring cause it says so much boring details, maybe it's friendly for beginners, but the developer should find materials fro themselves right? just make the target and development path clear.
• so this pa0 stuff does not meet my expection.

Reference

1. nemu project link