Add .md extension name in docs' link to make GitHub happy
PiperOrigin-RevId: 468723615
diff --git a/docs/struct_layout.md b/docs/struct_layout.md
index aecebd8..a85281d 100644
--- a/docs/struct_layout.md
+++ b/docs/struct_layout.md
@@ -50,7 +50,7 @@
NOTE: This has other, non-layout consequences for Rust: for example, it is not
safe to obtain two `&mut` references to overlapping objects, unless they are of
size `0`. (To prevent this, classes that might be base classes are always
-[`!Unpin`](unpin).)
+[`!Unpin`](unpin.md).)
This is impossible to represent in a C-like struct. (Indeed, it's impossible to
represent even in a C++-like struct, before the introduction of
