Adding the ability to create "draft" blog posts

[msholty-fd]

Hey there! Thanks for creating this template. I used it to deploy a blog in less than an hour, which is amazing considering previous attempts at creating a blogging website have been in vain for me because I spent so much time tinkering with the code instead of focusing on writing.

I added a bit of functionality to allow for "draft" posts so I could write posts and have folks proofread them live on my website. The idea is that you can access the post if you know the slug, but it doesn't appear in the list of posts. Here's the commit for how I did it. If you think it's worth bringing over to this repo, I'd be more than happy to open a PR for it. Let me know what you think!