初次向GitHub上传项目：
git init
git add README.md
git commit -m "first commit"
git remote add origin git@github.com:shimilygood/Home-wanglei2016.git
git push -u origin master
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git提交项目步骤：
git add .
git commit -m "first commit"
git remote add origin git@github.com:shimilygood/Home-wanglei2016.git
git push -u origin master //可以简化为git push
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git pull下拉数据