Rollup merge of rust-lang#75626 - GuillaumeGomez:cleanup-e0754, r=pickfire

Clean up E0754 explanation

r? @Dylan-DPC

cc @pickfire

Author: JohnTitor

src/librustc_error_codes/error_codes/E0754.md

@@ -1,31 +1,25 @@
 An non-ascii identifier was used in an invalid context.
 
-Erroneous code example:
+Erroneous code examples:
 
 ```compile_fail,E0754
 # #![feature(non_ascii_idents)]
 
-mod řųśť;
-// ^ error!
-fn main() {}
-```
-
-```compile_fail,E0754
-# #![feature(non_ascii_idents)]
+mod řųśť; // error!
 
 #[no_mangle]
-fn řųśť() {}
-// ^ error!
+fn řųśť() {} // error!
+
 fn main() {}
 ```
 
-Non-ascii can be used as module names if it is inline
-or a #\[path\] attribute is specified. For example:
+Non-ascii can be used as module names if it is inlined or if a `#[path]`
+attribute is specified. For example:
 
 ```
 # #![feature(non_ascii_idents)]
 
-mod řųśť {
+mod řųśť { // ok!
     const IS_GREAT: bool = true;
 }