Prune commentary and stale Rust port notes

src/lib.rs

@@ -7,13 +7,6 @@
 #![feature(option_into_flat_iter)]
 #![feature(async_fn_traits)]
 
-// Two windowing backends live side by side, chosen by target rather than by
-// feature flag: winit everywhere but Android, android-view on it. They are
-// mutually exclusive rather than both-compiled-in because winit's own
-// Android support pulls in `android-activity`, which needs one of its
-// `game-activity`/`native-activity` features selected -- exactly what
-// `iris-core` was kept free of, and android-view is the framework's own
-// answer to the same surface on that platform. See RUST.md's I2.
 #[cfg(target_os = "android")]
 pub mod android;
 #[cfg(not(target_os = "android"))]