I must be missing something as well, installing ScripthookVDOTNET doesn't add a scripts folder. Not at least following the instructions from https://www.gta5-mods.com/tools/scripthookv-net#comments_tab
I copy the files into the appropriate directory, which the instructions are not clear on...but there is no scripts folder. Must be steps missing somewhere as the step 3 directs which files which is odd because the download includes more files than the instructions detail.