Fix doc test

Author: Jonas Schievink

crates/ide-assists/src/handlers/convert_match_to_let_else.rs

@@ -14,6 +14,7 @@ use crate::{
 // Converts let statement with match initializer to let-else statement.
 //
 // ```
+// # //- minicore: option
 // fn foo(opt: Option<()>) {
 //     let val = $0match opt {
 //         Some(it) => it,

crates/ide-assists/src/tests/generated.rs

@@ -412,6 +412,7 @@ fn doctest_convert_match_to_let_else() {
     check_doc_test(
         "convert_match_to_let_else",
         r#####"
+//- minicore: option
 fn foo(opt: Option<()>) {
     let val = $0match opt {
         Some(it) => it,