Update README.md

Fix Bootstrap 5 link

Author: Timo-Breumelhof

README.md

@@ -6,7 +6,7 @@
 New (2023) DNN community site Theme.
 
 ## Dependencies
-- [Bootstrap 5](https://getbootstrap.com/docs/5.2/getting-started/introduction/)
+- [Bootstrap 5](https://getbootstrap.com/docs/5.3/getting-started/introduction/)
 - [StyleHelper](https://github.com/40fingers/StyleHelper-Sko)