[PATCH] doc: fix shattered.io link

["D. Ben Knoble" <ben.knoble@gmail.com>]

Since we published this document the domain has been taken over and no
longer reflects the original content. Link to the last good Web Archive
snapshot so folks can still retrieve the SHAttered information.

Suggested-by: Mae Eckert <mae.eckert@albellus.de>
Signed-off-by: D. Ben Knoble <ben.knoble@gmail.com>
---
 Documentation/technical/hash-function-transition.adoc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/technical/hash-function-transition.adoc b/Documentation/technical/hash-function-transition.adoc
index 241d2f763d..f6b38ddd50 100644
--- a/Documentation/technical/hash-function-transition.adoc
+++ b/Documentation/technical/hash-function-transition.adoc
@@ -29,7 +29,8 @@ advantages:
 
 Over time some flaws in SHA-1 have been discovered by security
 researchers. On 23 February 2017 the SHAttered attack
-(https://shattered.io) demonstrated a practical SHA-1 hash collision.
+(https://web.archive.org/web/20260207211148/https://shattered.io/)
+demonstrated a practical SHA-1 hash collision.
 
 Git v2.13.0 and later subsequently moved to a hardened SHA-1
 implementation by default, which isn't vulnerable to the SHAttered
-- 
2.53.0