Run azd provision error on Windows

[NanaXiong00]

Describe the issue:
When running azd provision on Windows, an error is displayed indicating a syntax rule error in the hook script as follows:

Repro Steps:

1. Clone the project.
2. Run python -m venv .venv and .venv\Scripts\activate.
3. Run pip install -r requirements.txt.
4. Run azd auth login.
5. Run npm i.
6. Run npm run env:init.
7. Run azd provision.

Environment:

• Azd version: azd version 1.9.6 (commit 0b1a8ad350177078312141f4465ad72205d7c077)
• OS: Windows desktop.

Expected behavior:
Run azd provision successfully.

@hemarina and @cwaddingham for notification.

[NanaXiong00]

@cwaddingham The issue described above can still be reproduced according to the latest code test. A code review found that the problem is preprovision.ps1 file in the code , where bash syntax was incorrectly used instead of powershell syntax.

[cwaddingham]

@NanaXiong00 please try it again.

[NanaXiong00]

@NanaXiong00 please try it again.

@cwaddingham Based on the latest code retest, the following error occurred:

• Run command npm run env:init:
  
• Run command azd provision:
  

[cwaddingham]

@NanaXiong00 given the number of issues that have come up with running this template on Windows we're going to remove support for that OS from it. Going forward, it will be supported on MacOS and Linux. We may revisit this in the future, but for now, this first iteration will be POSIX-only.

[NanaXiong00]

@cwaddingham While testing the template on macOS according to the instructions in README.md, the following issues were encountered:

It is recommended to include dependency installation steps in the README.md to prevent these issues.