Rollup merge of rust-lang#101915 - notriddle:notriddle/redirect, r=GuillaumeGomez

doc: fix redirected link in `/index.html`

Fallout from rust-lang#101166

Author: Dylan-DPC

src/doc/index.md

@@ -101,7 +101,7 @@ accomplishing various tasks.
 
 Many of Rust's errors come with error codes, and you can request extended
 diagnostics from the compiler on those errors. You can also [read them
-here](error-index.html), if you prefer to read them that way.
+here](error_codes/index.html), if you prefer to read them that way.
 
 # Master Rust