Allow running Node with env vars

[vjpr]

I find I have to pass a lot of flags via NODE_OPTIONS to get ESM and other experimental features to work.

This Node package allows you to pass env vars to Node: https://github.com/toddbluhm/env-cmd

But it adds 300ms to startup time - toddbluhm/env-cmd#349

I would love to use dum instead.

a. Support running a cross-platform script (.sh / .ps1 / .bat)

Essentially just doing the following (maybe reading location of script files from package.json or another env var):

I would be sharing script files from <package>/node_modules/my-scripts/scripts/(run-win.ps1|run-nix.sh).

https://stackoverflow.com/a/68934424/130910

{
    "scripts": {
        "build": "( Write-Output 'Powershell' && ./tools/build-ps.ps1 ) || 
                  ( CALL ./tools/build-cmd.bat ) || 
                  ( bash -c 'uname -a | grep -q -i Linux' && bash -c ./tools/build-linux.sh ) ||
                  ( bash -c 'uname -a | grep -q -i Darwin' && bash -c ./tools/build-mac.sh )"
        }
}

b. Support .env, etc.

This is lower priority for me. Replicates the functionality of https://www.npmjs.com/package/env-cmd