Is there a tutorial on how to make plugins for New Gen??

I was just wondering if there is a starting point for making add-ons such as TESH for New Gen WorldEdit. I was just hoping to make a small add-on that would check for minor syntax errors(Not check the whole document like pjass) as you are typing so that when I make mistakes like doing syntax for Java instead of Jass(because I do that subconsciously, ussually just forgetting to put a set or most likely forgetting to put a then on the end of an if-then) it would just do a red underline or the sort. And from there maybe even more than just that.

Thanks for any help.

There is no such tutorial as the target audience is pretty small and there are numerous ways how you could interface with NewGen.
For what you have planned it'd be best to extend TESH accordingly. So I'd start by askin SFilip for the source code of TESH and the allowance to edit it of course.