Add rustfmt.toml for explicit styling (#348)

* Propose an explicit .rustfnt.toml
Use 2024 style, 4 spaces for tabs and epand the default width a tad

* Auto-format the existing code with new rules

lan-mouse-ipc/src/connect_async.rs

@@ -1,7 +1,7 @@
 use crate::{ConnectionError, FrontendEvent, FrontendRequest, IpcError};
 use std::{
     cmp::min,
-    task::{ready, Poll},
+    task::{Poll, ready},
     time::Duration,
 };