adds nodejs support

[idkjs]

Nice project. Thanks for sharing it.

You probably dont need it but here it is anyway. I added a few line to check if on browser or node and select XmlRequest based on the environment.

[eWert-Online]

Hey 👋 thank you for creating this pr. What problem does this solve exactly? 😊

[idkjs]

I tried using your lib to run some xmlrequests to test some queries and it failed. Figured just patch it which I did but trying to be a good netizen and sharing it. Thanks again for sharing.