You can post this sort of thing without the Show HN but Show HN itself is for a more specific kind of thing, take a look at https://news.ycombinator.com/showhn.html

Show HN is for something you've made that other people can play with. HN users can try it out, give you feedback, and ask questions in the thread. On topic: things people can run on their computers or hold in their hands. For hardware, you can post a video or detailed article. For books, a sample chapter is ok.

Off topic: blog posts, sign-up pages, newsletters, lists, and other reading material. Those can't be tried out, so can't be Show HNs. Make a regular submission instead.