Remove mention of the untagged_unions nightly feature
//! ## the `--nightly` flag
//!
//! The `--nightly` flag can be passed to `svd2rust` to enable features in the generated api that are only available to a nightly
-//! compiler. These features are
-//!
-//! - `#[feature(untagged_unions)]` for overlapping/overloaded registers
-
+//! compiler. Currently there are no nightly features the flag is only kept for compatibility with prior versions.
#![recursion_limit = "128"]
#[macro_use]
