Rollup merge of #160088 - cuishuang:fix_404_url, r=GuillaumeGomez

fix 404 url in src/doc/rustdoc.md

fix 404 url in src/doc/rustdoc.md

The previous link will lead to a 404 page.

<img width="2744" height="1238" alt="image" src="https://github.com/user-attachments/assets/b1c81c69-2181-4cb1-8a06-83e7b32ebd6c" />

Author: JonathanBrouwer

src/doc/rustdoc.md

@@ -1,3 +1,3 @@
 % Rust Documentation
 
-This has been moved [into the rustdoc book](rustdoc/index.html).
+This has been moved [into the rustdoc book](rustdoc/src).