Idea add git journal functionality

[Th3Whit3Wolf]

Firstly this project is awesome! This if my first real git hook application I've ever used. I've taken a look at a few but a lot of them required everyone to have application installed. I love that the only requirement for this is to be working on rust, my favorite language.

I have been using git journal for awhile. It is also written in rust, it helps the user write good commit messages and can generate changelog. It would be cool if cargo husky had this functionality so that I wouldn't need to install git-journal.

Also in your readme regarding user hooks, it doesn't specify about how to write user hooks. Given the scope of the project someone may think that a user hook allows them to run rust files as user hooks.