create a new repository on the command line
echo "# <RepositoryName>" >> README.md
git init
git add README.md
git commit -m "first commit"
git remote add origin https://github.com/**<gituserID>/<RepositoryName>**.git
git push -u origin master
push an existing repository from the command line
git remote add origin https://github.com/**<gituserID>/<RepositoryName>**.git
git push -u origin master