add heroku to git remote code example

Example 1: git remote add heroku

heroku git:remote -a project

Example 2: git push to heroku

$ git push heroku master

Example 3: heroku git remote

heroku git:remote -a name-of-app

Example 4: set git remote heroku to https://git.heroku.com/resume-projects.git

$ heroku git:remote -a thawing-inlet-61413
set git remote heroku to https://git.heroku.com/thawing-inlet-61413.git