Regarding styles part

I am just wondering, even though `hindent` is a great tool I find it working better with `stylish-haskell`. This way the code almost always looks pretty cool. This is how IntelliJ-haskell formatting works, it uses both tools under the hood [proof-link](https://github.com/rikvdkleij/intellij-haskell#getting-started). There is a separate tool called `hfmt` which provides both `hindent` and `stylish-haskell` formatting and works kinda like `gofmt`. Also, there is already [plugin for VS Code](https://github.com/sergey-kintsel/hfmt-vscode).
WDYT?

No repository file, test, or entry point is named. Start by reviewing the linked IntelliJ Haskell, hfmt, and hfmt-vscode references, then determine whether rio should integrate or document combined hindent and stylish-haskell formatting; the issue does not define a concrete done state.

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