Tools for scaling up -> web links need to be checked

[JacekHoleczek]

For example, I noticed that in the "Tools for scaling up" chapter, the "Uproot" link is "[GitHub](https://github.com/scikit-hep/uproot4)" (note "uproot4", but it should be "uproot5" now).

BTW. Well, I think I am done with going through the tutorial.

[jpivarski]

For what it's worth the URL redirects. (I've left a lot of uproot4 URLs in my local bookmarks.)

Thanks for all of your feedback!

[stale]

This issue or pull request has been automatically marked as stale because it has not had recent activity. Please manually close it, if it is no longer relevant, or ask for help or support to help getting it unstuck. Let me bring this to the attention of @klieret @wdconinc @michmx for now.