update fork github app code example

Example 1: update fork repository

## Add Original Repository
git remote add upstream https://github.com/OriginalOwner/OriginalProject.git

## Verify if Repository is added
git remote -v

## Fetch Updates from Original Repository
git fetch upstream

## Checkout to your master branch
git checkout master

## Get Updates from upstream repo
git merge upstream/master

## Push the commit over 
git push origin master

Example 2: git update fork from original repo

$ git remote add upstream https://github.com/[Original Owner Username]/[Original Repository].git
$ git fetch upstream
$ git checkout master
$ git merge upstream/master
$ git push