add closing paren

src/guides/getting-started.md

@@ -391,7 +391,7 @@ Any time we run or revert a migration, this file will get automatically updated.
 
 Using `#[derive(Queryable)]` assumes that the order of fields on the `Post` struct matches
 the columns in the `posts` table, so make sure to define them in the order seen in the `schema.rs` file.
-Using `#[derive(Selectable)]` in combination with [`SelectableHelper::as_select`] ensures that the field order always matches. The `#[diesel(check_for_backend(diesel::pg::Pg)]` attribute provides a further check that all field types match which what your query is returning. This attribute can improve the error messages generated by the compiler significantly.
+Using `#[derive(Selectable)]` in combination with [`SelectableHelper::as_select`] ensures that the field order always matches. The `#[diesel(check_for_backend(diesel::pg::Pg))]` attribute provides a further check that all field types match which what your query is returning. This attribute can improve the error messages generated by the compiler significantly.
 
 [`SelectableHelper::as_select`]: https://docs.diesel.rs/2.2.x/diesel/prelude/trait.SelectableHelper.html#tymethod.as_select