To create a list of your installed VS Code extensions, you can use the following PowerShell command:
code --list-extensions > C:\Temp\VSCodeExtensions.txt
# To create a list of extensions to install:
code --list-extensions | % { "code --install-extension $_" } > C:\Temp\VSCodeExtensions.txt
Alternatively, you can use the Settings Sync extension to export your VS Code extensions and configuration.