Update changelogs from fern repo (#562)

Co-authored-by: dsinghvi <[email protected]>

Author: fern-support

fern/products/cli-api-reference/cli-changelog/2025-08-18.mdx

@@ -1,3 +1,20 @@
+## 0.66.21
+**`(feat):`** Introduce an OpenAPI setting called `inline-all-of-schemas` which recursively 
+visits the scheme definitions of allOf schemas and inlines them into the child. 
+
+The benefit of doing this is that a child schema can modify whether or not a parent 
+property is required. Without this setting, Fern would ignore the child schema's 
+declaration of optional and prefer the parent schema's instead. 
+
+Add the following to your `generators.yml`: 
+
+```yml generators.yml 
+api: 
+  settings: 
+    inline-all-of-schemas: true
+```
+
+
 ## 0.66.20
 **`(fix):`** Add `kwargs` as a reserved word in python so that generated SDKs continue to compile.