Components: express, path, router, pug
steps:
npm init -y
emacs server.js
npm install express --save
node server.js
set a repository in github account
git init
git status
git add ......
git commit -m "setup"
git remote add origin ......
git push -u origin master
git log
git log --abbrev-commit
git tag -a v1 -m "express_start setup"
git tag