SE-0425: Add review thread (#2352)

Author: DougGregor

proposals/0425-int128.md

@@ -5,7 +5,7 @@
 * Review Manager: [Doug Gregor](https://github.com/DougGregor)
 * Implementation: https://github.com/stephentyrone/swift-numerics/tree/int128
 * Status: **Active Review (March 5...19, 2024)**
-* Review: ([Pitch](https://forums.swift.org/t/pitch-128-bit-integer-types/70188))
+* Review: ([Pitch](https://forums.swift.org/t/pitch-128-bit-integer-types/70188)) ([Review](https://forums.swift.org/t/se-0425-128-bit-integer-types/70456))
 
 ## Motivation