Read from stdin and format to stdout

It would be great for editor support if running cljfmt with no arguments read code from stdin and formatted it to stdout. Practically all other code formatters I've come across can do this. One of them is https://github.com/snoe/node-cljfmt which is a similar project to speed up cljfmt (but using Node instead of Graal). It would be great if the Node-based and Graal-based cljfmt commands had identical command line syntax (perhaps they could even be merged into one project - I don't know whether that's practical).