fix crash on index error due to hyperlink at the end of the file

src/main.rs

@@ -215,7 +215,7 @@ fn preprocess(string: String) -> String {
     let start_delims = vec![b'(', b'<'];
     let end_delims = vec![b')', b'>'];
     let links = finder.links(result.as_str()).filter(|link| {
-        (link.start() == 0 || link.end() == result.len())
+        (link.start() == 0 || link.end() == result.len() - 1)
             || (!start_delims.contains(&result_vec[link.start() - 1])
                 && !end_delims.contains(&result_vec[link.end() + 1]))
     });