Add zsh & PowerShell options for Code Builder terminal window

Is your feature request related to a problem? Please describe.
A clear and concise description of the problem. For example: I'm always frustrated when [...]

Goal

I want parity between desktop VS Code and Code Builder terminal options so that I can easily move between them without having to setup/install or worse, re-write code.

• MacOS: Starting in 2019 (Catalina) MacOS switched from Bash as the default shell to zsh. I tried apt-get install zsh but it needs admin and sudo command isn't found
• Windows: Windows includes PowerShell by default and is an option in the terminal window. Install PowerShell via apt-get

Describe what you are ultimately trying to do
What is your use case, how might you do this today?

I have custom zsh scripts (I imagine Windows customers have custom PowerShell scripts) for common automation tasks that I want to use, including my profile .zshrc profile with command aliases.

Ex:

alias screenshot="chrome --headless --disable-gpu --screenshot"
alias html="chrome --headless --disable-gpu --dump-dom"
alias glog="git log --pretty=format:'%h - %an: %s' --graph"

screenshot https://developer.salesforce.com - Auto-saves a screenshot of the web page
html https://developer.salesforce.com - Writes html for headless chrome to standard output (or pipe/filter as needed)
glog Shows a pretty view of git commits/branches to standard output

Describe how you think Code Builder can help solve your problem or improve your work
A clear and concise description of what you want to happen.

Seamless move from desktop to web

Additional context
Add any other context or screenshots about the feature request here.

Use issue #133 as the requirements starting point: compare the existing Code Builder terminal options with desktop VS Code, then verify how zsh and PowerShell availability and profiles such as .zshrc are handled. Done means Code Builder offers both requested shell options and supports the stated profile and script use cases; no file or test is named in the issue.