update contribution guide for better work flow

CONTRIBUTING.md

@@ -7,4 +7,20 @@ This guide will help us ensure that you have a simple and effective way to contr
 - Make sure you check your spelling and grammar.
 - Create individual PR for each suggestion.
 
+> Tip: Keep your `master` branch pointing at the original repository and make
+> pull requests from branches on your fork. To do this, run:
+>
+> ```
+> git remote add upstream https://github.com/florinpop17/app-ideas.git
+> git fetch upstream
+> git branch --set-upstream-to=upstream/master master
+> ```
+>
+> This will add the original repository as a "remote" called "upstream,"
+> Then fetch the git information from that remote, then set your local `master`
+> branch to use the upstream master branch whenever you run `git pull`.
+> Then you can make all of your pull request branches based on this `master`
+> branch. Whenever you want to update your version of `master`, do a regular
+> `git pull`.
+
 Thank you for spending your time to improve this project! ^\_^