Reference: Import existing source code to GitHub

If you’ve got local source code you want to add to a new remote new git repository without ‘cloning’ the remote first, do the following (I often do this – you create your remote empty repository in bitbucket/github, then push up your source)

1. Create the remote repository, and get the URL such as git@github.com:/youruser/somename.git or https://github.com/youruser/somename.gitIf your local GIT repo is already set up, skips steps 2 and 3
2. Locally, at the root directory of your source, git init2a. If you initialize the repo with a .gitignore and a README.md you should do a git pull {url from step 1} to ensure you don’t commit files to source that you want to ignore ;)
3. Locally, add and commit what you want in your initial repo (for everything, git add . then git commit -m 'initial commit comment')
4. to attach your remote repo with the name ‘origin’ (like cloning would do)
   git remote add origin [URL From Step 1]
5. Execute git pull origin master to pull the remote branch so that they are in sync.
6. to push up your master branch (change master to something else for a different branch):
   git push origin master

https://stackoverflow.com/a/8012698/61902