docs(readme): add credits to the parent repository

Signed-off-by: M. Fatih Cırıt <[email protected]>

README.md

@@ -95,3 +95,10 @@ Please install [Code Spell Checker](https://marketplace.visualstudio.com/items?i
     }
 ]
 ```
+
+## Credits
+
+This repository was mirrored from [tier4/autoware-spell-check-dict](https://github.com/tier4/autoware-spell-check-dict) on **2024-11-27**.  
+The original repository was created by [Tier IV, Inc.](https://tier4.jp/en/).
+
+We extend our gratitude to the original authors and contributors for their efforts and dedication.