docs: add clarification title for Overlay

jamietanna · jamietanna · commit 85c4b48c271e · 2025-05-04T19:54:19.000+01:00
To improve searching.
diff --git a/README.md b/README.md
@@ -2037,7 +2037,7 @@ If you don't want to do this, an alternate option is to [use a single package, w
 
 Check out [the import-mapping/multiplepackages example](examples/import-mapping/multiplepackages/) for the full code.
 
-## Modifying the input OpenAPI Specification
+## Modifying the input OpenAPI Specification (with OpenAPI Overlay)
 
 Prior to `oapi-codegen` v2.4.0, users wishing to override specific configuration, for instance taking advantage of extensions such as `x-go-type`  would need to modify the OpenAPI specification they are using.
 
