[no-ci] Update README.md

Author: lemire

README.md

@@ -5,7 +5,8 @@ That is, we see to build fast and convenient code to map your data structure to
 
 Ultimately, this work might cover both serialization and deserialization.
 
-We've seen different proposals for C++ reflection, for now we will focus on the [latest p2996 paper](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2024/p2996r4.html) that is targeting C++26.
+We've seen different proposals for C++ reflection, for now we will focus on the [latest p2996 paper](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2024/p2996r5.html) that is targeting C++26.
+
 
 Table of Contents
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