Man pages for bashblog!

I've managed to consolidate the information from the README.md and from within bb.sh itself into a fresh new manpage.

I've opened a [pull request](https://tildegit.org/club/bashblog/pulls/3). You can fetch the manpages and run `man ./bb.1.mdoc` to look at it. It's pretty nice. I find it better than having to go through the script to understand what it can do.

tags: posts, manpages, git