how to add .gitignore to repository code example

Example 1: create gitignore

# creates gitignore file
$ touch .gitignore

Example 2: git add gitignore

$ touch .gitignore

Example 3: what to add to gitignore

Look at this awesome site!
https://www.toptal.com/developers/gitignore
Generates a gitignore for you, based on the technologies you're using

Example 4: what is add.gitignore

The purpose of gitignore files is to ensure that certain files not tracked by git remain untracked.