Add zsh & PowerShell options for Code Builder terminal window

[thedanfernandez]

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
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