Post History

Prompted by [this new answer to this meta question](https://scientific-speculation.codidact.com/posts/293812/295203#answer-295203):

This community has very low activity right now, and I wonder if posts in a different category would be missed.  It is possible for questions and articles to sit alongside each other in the same category, at the small cost of one extra prompt for post type when starting a post.  I'd like to see this community succeed (and it will probably morph along the way), so how about allowing articles right there on the main page?  You can see an example of a category that supports both post types on [Collab](https://collab.codidact.org/categories/56), our community for people developing the platform or setting up other networks using it.  On a larger and more active community it would make sense to separate these, like Electrical Engineering does for papers, but Scientific Speculation isn't there yet.  If this community grows large enough to want to separate this content, posts can be moved to another category later.

We should be welcoming people with questions, answers, and information to share, and our current structure cuts off some of that.  Let's do something about that.