This is enough to make NP++ a fail software. No options to create an xhtml strict/transitional template or any other file templates. Sure you can use macros to record and create your own, but you will have to type the entire doctype and tags for each one. Not really trolling here, just stating the truth.
To add to this, why not just allow users to choose what file they want to create when they go to file> new …instead of creating a normal txt file and then needing the user to choose the language. It saves steps.