Make rustywind available as library

[bram209]

I maintain a formatter for the rust leptos framework and would like to use rustywind as a library (mainly this function: https://github.com/avencera/rustywind/blob/fe487da5ceecd5c0d2377796b063d53addf799e4/src/sorter.rs#L34C11-L34C67)

Would you be willing to add a lib.rs next to the main.rs, so that your binary imports from the library instead? This way I can include tailwind class sorting seamlessly in my project (without having to go through the hassle of spawning a new process that calls the CLI).