🐛 copyright symbol not recognized on Windows - use ASCI complient spelling

- maybe unicode symbols could be used?

Author: enryh

src/vuegen/utils.py

@@ -810,7 +810,7 @@ def generate_footer() -> str:
     <a href="https://github.com/Multiomics-Analytics-Group/vuegen" target="_blank">
         <img src="https://raw.githubusercontent.com/Multiomics-Analytics-Group/vuegen/main/docs/images/vuegen_logo.svg" alt="VueGen" width="65px">
     </a>
-    | © 2025 <a href="https://github.com/Multiomics-Analytics-Group" target="_blank">
+    | Copyright 2025 <a href="https://github.com/Multiomics-Analytics-Group" target="_blank">
         Multiomics Network Analytics Group (MoNA)
     </a>
 </footer>"""