When I first discovered Bootstrap (and web development), I thought it had the best templates and was a really good place to start making a website. I noticed that there were sign in and sign up buttons that I thought would work. I then learned that I needed PHP to make those buttons work. Being the beginner that I was, I searched the internet for something to make the whole thing work (with the users). I could not find anything. I just wanted to use the bootstrap templates with full functionality without having to do a lot of work. So, what did I do? I learned PHP and many other languages to build this. I want this to be very useful to people, so that people don't have to do all the work that I did to make it.
Or, if you want to get clever, add it to a Composer repo, and have a shell script run after the update that copies stuff from the vendor folder into /public (that tripped me up on pagodabox but it's doable) and now you have Bootstrap running with auto updating and dependency management.
Why does this need to be a service?