Update README.md

Signed-off-by: Code Ninja <[email protected]>

Author: NinjaRocks

README.md

@@ -58,7 +58,7 @@ If you are having problems, please let me know by [raising a new issue](https://
 This project is licensed with the [MIT license](LICENSE).
 
 ## Version History
-The main branch is now on .NET 8.0. The following previous versions are available:
+The main branch is now on .NET 9.0. The following previous versions are available:
 | Version  | Release Notes | Developer Guide |
 | -------- | --------|--------|
 | [`v4.0.0`](https://github.com/CodeShayk/FeatureOne/tree/v4.0.0) |  [Notes](https://github.com/CodeShayk/FeatureOne/releases/tag/v4.0.0) | [Guide](https://github.com/CodeShayk/FeatureOne/blob/v4.0.0/DeveloperGuide.md) |