how to add a gitignore to a repository code example
Example 1: apply gitignore to current commit
#First commit all changes
git rm -r --cached .
git add .
git commit -m ".gitignore updated"
Example 2: 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