New layout for the frontpage and added subcategories!

We have quite a variety of topics on here now, so I thought it needed a bit more organization. I’ve switched it to use the category overview as the main page now, so we can see more into the other topics. I also added various subcategories to organise things a bit better!

We’d actually like to use the forum for writing more stuff we’re doing in karrot, we also have a rocket chat (at… so let’s see how it goes.