Update 01-chapter3.markdown

It’s worth noting here that the work you did in your hotfix branch is not contained in the files in your iss53 branch. If you need to pull it in, you can merge your master branch into your iss53 branch by running git merge master, or you can wait to integrate those changes until you decide to pull the iss53 branch back into master later.
Merge pull request #540 from better0332/patch-1

Update 01-chapter3.markdown