Add compatibility info to lints

compiler/rustc_error_codes/src/error_codes/E0782.md

@@ -18,7 +18,7 @@ simply a heap allocated type called `Foo`.
 
 To fix this issue, add `dyn` before the trait name.
 
-```
+```edition2021
 trait Foo {}
 fn test(arg: Box<dyn Foo>) {} // ok!
 ```

compiler/rustc_error_codes/src/error_codes/E0783.md

@@ -14,7 +14,7 @@ ranges which are now signified using `..=`.
 
 To make this code compile replace the `...` with `..=`.
 
-```
+```edition2021
 match 2u8 {
     0..=9 => println!("Got a number less than 10"), // ok!
     _ => println!("Got a number 10 or more"),