-this repository is for storing our source code online
-we can 'push', means that upload the changes we made to this repo
-we also can 'pull', means download the source code from this repo to vs code
############################# NOTICE ########################################## -PLEASE DO NOT EDIT ANYTHING IN THIS BRANCH.
-PLEASE MAKE SURE EVERYTIME YOU WANT TO EDIT THE SOURCE CODE IN THE REPO, YOU CHOSE EDIT BRANCH NOT MAIN BRANCH
-MAKE SURE YOU'RE IN THE RIGHT BRANCH WHEN YOU WANT TO EDIT THE SOURCE CODE IN THE VS CODE