If all you do is web development, all programming languages look like tools to build web sites with I guess. I don't think the author was trying to sell anything, it seemed like more of a gift to like-minded individuals.
HowIStart isn't something that I'd considering "marketing" for the language, personally. It does what it says on the tin: teach you how to get started from scratch with the language.
However, you are correct somewhat; this is why on Nim's homepage[0] there is an example of Jester (a web server/routing DSL)!