adds ome advice

diff --git a/rust/pspp/src/sys/mod.rs b/rust/pspp/src/sys/mod.rs
index e99770fdce9326e9c4990b68e85e12e0bdda8025..94e063fcf1eec4545663a5cb7221741cb8b43161 100644 (file)
--- a/rust/pspp/src/sys/mod.rs
+++ b/rust/pspp/src/sys/mod.rs
@@ -21,6 +21,8 @@
 //! evolved greatly over that time to support new features, but in a way to
 //! facilitate interchange between even the oldest and newest versions of
 //! software.
+//!
+//! To read a system file in the simplest way, use [ReaderOptions].
 
 // Warn about missing docs, but not for items declared with `#[cfg(test)]`.
 #![cfg_attr(not(test), warn(missing_docs))]