Correct delimiter positions

j counts from 0, so add the start value. Also ensure it is never equal
to i, or we get confused by delimiters where the open and close tokens
are the same (such as `|foo|` in Rust).

src/tree_sitter_parser.rs

@@ -287,9 +287,9 @@ fn find_delim_positions(
     for (i, token) in tokens.iter().enumerate() {
         for (open_delim, close_delim) in lang_delims {
             if *token == Some(open_delim) {
-                for (j, token) in tokens.iter().skip(i).enumerate() {
+                for (j, token) in tokens.iter().skip(i + 1).enumerate() {
                     if *token == Some(close_delim) {
-                        return Some((i, j));
+                        return Some((i, i + 1 + j));
                     }
                 }
             }