Use `purty` as formatter

[timjs]

I'd love to have purty format when I save a PureScript file!

However, is ide-purescript the right package to implement this? Or should it be added to beautify for example?

[nwolverson]

Looking at beautify, looks like it might be appropriate, no sense in reinventing the wheel here?

Don't think we get any leverage having it here, it doesn't integrate with LSP/compiler tooling. Only concern may be not sure where beautify hooks into for triggering on save, if the file is reformatted before saving things will be great, if it effectively gets saved twice (like a disk file watcher would) it could be less great for LSP integration (rebuilding twice for example).

[nwolverson]

Though looks like they're doing a 'stop and rewrite the world' for the last couple of years so might not be a quick contribution

[nwolverson]

This is now in the LSP, should look at integrating

[FbN]

Simple Atom Package that calls Purty