update heroku app code example

Example 1: git push to heroku

$ git push heroku master

Example 2: heroku and github on termi

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

Example 3: how to update heroku

heroku update
#(OR)
sudo apt update && sudo apt install heroku
# to update heroku

Example 4: how to update heroku terminal

$ brew tap heroku/brew && brew install heroku

Example 5: heroku and github on termi

$ git remote rename heroku heroku-staging