Keeping the IDs in sync

[eric-fleming]

I found your article on Dev.to to learn more about React, THANKS!
I noticed that the indexes were off when someone creates or deletes users.

• Originally the first new user index was one ahead.
• Also deleting records made it possible to have multiple copies of the same ID since it was tied to length.

TLDR: I made a new state variable to keep track of the last user ID.