* Cleaned up usage.md for clarity, formatting, and grammar.
While working on it, I hard-wrapped the lines to 80 characters. Hope that doesn't complicate things.
Note: I changed the Steve Buscemi quote to maintain compliance with the Code of Conduct.
* more changes to the usage page
Includes information about two new functions (`--delete`) and (`-contains`).
It's starting to look quite different from the original...
These kinds of jokes make us look bad, and have gotten this project bad
PR on social media. It's best to get rid of them. We can still be super
glib and funny without crass jokes.
