Implement the new fields for plain link.

src/parser/plain_link.rs

@@ -54,7 +54,7 @@ pub(crate) fn plain_link<'b, 'g, 'r, 's>(
     let (remaining, _) = pre(context, input)?;
     let (remaining, path_plain) = parse_path_plain(context, remaining)?;
     peek(parser_with_context!(post)(context))(remaining)?;
-    let (remaining, _trailing_whitespace) =
+    let (remaining, post_blank) =
         maybe_consume_object_trailing_whitespace_if_not_exiting(context, remaining)?;
     let source = get_consumed(input, remaining);
     Ok((
@@ -66,6 +66,7 @@ pub(crate) fn plain_link<'b, 'g, 'r, 's>(
             raw_link: path_plain.raw_link,
             search_option: path_plain.search_option,
             application: path_plain.application,
+            post_blank: post_blank.map(Into::<&str>::into),
         },
     ))
 }