Test npm packages locally in another project using npm link

We will import our newly published package into a new project locally to make sure everything is working as expected. We can do this locally before publishing with npm link. This creates a symbolic link in our node_modules folder, so our unpublished local package is used like an installed published package. This is important because it lets us test making changes to our package and using them immediately without publishing and updating a package with each change we want to test. This is good practice to do before publishing a new version of a package.