Add oh-my-zsh and update Mac users to zsh

[twalton83]

Title	Author	Date
Update to zsh	Tati	12.28.21

Update Mac users to OMZ

Summary

given that zsh is the new default shell, we should bake in instructions to update to zsh. Further, we should consider

Motivation

We get a frequent amount of questions by bash Mac users confused by the update prompt. We also want to consider that vanilla bash/zsh is hard to read, and oh-my-zsh has themes that are highly supported and make the terminal easier to read.

Suggested implementation

Update installation lessons to include the update for users who are seeing the prompt.

Drawbacks

• Might add confusion to new users.

Alternatives

• Bash themes?

Additional