[README] Hyperlink to successor project: Ultimathnum.

Author: oscbyspro

README.md

@@ -7,7 +7,7 @@
 | 0.17.0  | 5.7   | 14.0  | 14.0         | 11.0  | 14.0  | 7.0     |
 
 > [!IMPORTANT]
-> The development of this project has moved elsewhere.
+> The development of this project has moved over to [**Ultimathnum**](https://github.com/oscbyspro/Ultimathnum).
  
 > It turns out that I need \~(\~(x)) to equal x for all x.\
 > This is not possible with arbitrary unsigned integers at the moment.\