How to turn existing folder into Git repo
Have a directory that you want to be linked to a Git repo ?
Code
Replace https://github.com/zhenyufu/zhenyufu.github.io.git with your repo url:
git init
git remote add origin https://github.com/zhenyufu/zhenyufu.github.io.git
git pull origin master
git add .
git commit -m 'added files'
git push origin master