Update changelogs from fern repo (#4436)

Co-authored-by: iamnamananand996 <31537362+iamnamananand996@users.noreply.github.com>

Author: fern-support

fern/products/sdks/overview/rust/changelog/2026-03-20.mdx

@@ -1,3 +1,9 @@
+## 0.19.11
+**`(fix):`** Use `&str` instead of `&String` in generated method signatures, union getter methods,
+and undiscriminated union accessor methods. `&str` is more idiomatic Rust and more
+flexible, accepting both `&String` and string literals.
+
+
 ## 0.19.10
 **`(fix):`** Replace `unwrap_or_default()` with proper error propagation via `map_err(ApiError::Serialization)?`
 when serializing request bodies with `serde_json::to_value`. Previously, serialization failures