Re-title unsafe extern

Author: cuviper

posts/2024-10-17-Rust-1.82.0.md

@@ -156,7 +156,7 @@ Relaxing this may cause problems where some unsafe blocks are now reported as un
 
 A future version of Rust is expected to generalize this to other expressions which would be safe in this position, not just statics.
 
-### Unsafe extern
+### Safe items in `unsafe extern`
 
 Rust code can use functions and statics from foreign code.  The type signatures of these foreign items are provided in `extern` blocks.  Historically, all items within `extern` blocks have been unsafe to call, but we didn't have to write `unsafe` anywhere on the `extern` block itself.