Update man page to latest PNG 3e draft

png.5

diff --git a/png.5 b/png.5
index 16c1032..31075de 100644
--- a/png.5
+++ b/png.5
@@ -20,10 +20,10 @@
 .SH "SEE ALSO"
 .BR "libpng"(3), " zlib"(3), " deflate"(5), " " and " zlib"(5)
 .LP
-PNG Specification (Third Edition) Candidate Recommendation Draft, July 2024:
+PNG Specification (Third Edition) Candidate Recommendation Draft, January 2025:
 .IP
 .br
-https://www.w3.org/TR/2024/CRD-png-3-20240718/
+https://www.w3.org/TR/2025/CRD-png-3-20250121/
 .LP
 PNG Specification (Second Edition), November 2003:
 .IP