Update changelogs from fern repo (#5410)

Co-authored-by: dsinghvi <10870189+dsinghvi@users.noreply.github.com>

Author: fern-support

fern/products/cli-api-reference/cli-changelog/2026-05-06.mdx

@@ -1,3 +1,12 @@
+## 5.16.1
+**`(fix):`** `fern check` now accepts changelog navigation entries whose URL has any
+allowlisted segment (e.g. `whats-new`, `release-notes`, `changelog`),
+not just the trailing one. This means a changelog page like
+`/whats-new/product-updates` no longer raises a false-positive error
+about RSS / Atom / JSON feeds 404ing — the docs server matches the
+same loosened rule when serving feeds.
+
+
 ## 5.16.0
 **`(feat):`** cli-v2: `fern check` now prints rich, Rust-style errors for MDX/Markdown
 parse failures. Each error includes a stable error code (e.g. `E0301`),