What is the best practice for handling common files on GitHub?

I have been trying to google this for a while with non success. I am working on a project that uses normalize.css and a few common JavaScript libraries. My question is should I be uploading these resources to GitHub even though they are commonly avalible or is there more acceptable method to allow others who might fork the repo know they need to add things like react or normaize?

As long as they are open source, it’s perfectly fine to modify and build on existing code. However, you don’t really need to include the entire repository of, say React, on your repo, just put the relevant files (usually something like react.min.js or react.dom.js) in a folder.

If you are using a package manager like yarn, bower or npm, put the name of the dependency folder in a .gitignore file. Also, you can put normalize.css and the common JavaScript libraries you use in the .gitignore file.

Thanks to both of you for your help.