Update changelogs from fern repo (#1365)

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

Author: fern-support

fern/products/sdks/overview/csharp/changelog/index.mdx

@@ -1,3 +1,7 @@
+## 1.0.0-rc30
+**`(feat):`** Add support for custom Gemfiles.
+
+
 ## 1.0.0-rc29
 **`(feat):`** Add support for API key (header-based) authentication in Ruby SDK generator.
 Supports multiple authentication schemes in the same API.