Update changelogs from fern repo

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

@@ -1,3 +1,25 @@
+## 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`),
+a `--> path:line:col` location, two surrounding source lines with a
+caret pointer, and an inline `fix:` suggestion when one is available.
+
+
+**`(feat):`** cli-v2: add interactive AI-assisted fixes for MDX/Markdown parse errors.
+`fern check` now offers to apply a fix when run interactively — using a
+deterministic string-replace when the parser's `fix:` hint matches the
+file, and falling back to a configured AI provider otherwise. Provider
+is selected via `fern config ai set-provider <anthropic|openai|bedrock>`
+and credentials via `fern config ai set-key <key>` (Bedrock uses the
+standard AWS environment). Prompts are skipped automatically when
+running inside a Claude Code session (`CLAUDECODE=1`).
+
+
+**`(feat):`** cli-v2: when `fern check` finds multiple MDX errors, prompt once for a
+batch action ("apply all", "review each", "skip all") instead of
+prompting once per error.
+
+
 ## 5.15.3
 **`(fix):`** Fix `fern check` to respect `x-fern-ignore` when validating duplicate SDK method names. Operations marked with `x-fern-ignore: true` are now excluded from the duplicate override check.