Document and expose public members for Rojo API

src/session_id.rs

@@ -1,6 +1,10 @@
 use serde::{Deserialize, Serialize};
 use uuid::Uuid;
 
+/// A randomly generated ID generated by Rojo during a serve session.
+///
+/// If the session ID of the server changes between requests, that indicates
+/// that a new server has started up and the session should be terminated.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
 pub struct SessionId(Uuid);