`cabal-prettify`: Prettify your Cabal package configuration files!

Quick start:

Prettify the configuration file of the package you are in right now:
```
cabal-prettify --this
```

Prettify specified configuration files:

cabal-prettify cabal-prettify.cabal examples/**/*.cabal

Prettify standard input:

cabal-prettify --filter < cabal-prettify.cabal

Tidy up the directory structure:
```
cabal-prettify --this --move
```
Check but do not modify, exit successfully if everything is already well formatted:
```
cabal-prettify --this --check
```
Automatically add all Haskell files to exposed-modules or other-modules:
```
cabal-prettify --this --expose
```

Prettified files are backed up with the extension *.backup.
1. Files that are already pretty are not backed up.
  
  This ensures that running cabal-prettify twice in a row does not overwrite the original.