fix: optimize file type check

- Use a more specific regex check
- Use `test` method instead of `match`

Refs: #1224, #1225

src/NeonCore.ts

@@ -206,7 +206,7 @@ class NeonCore {
             }
           }).then(data => {
             // Check if the MEI file is sb-based. If so, convert to staff-based.
-            if (!data.match(/.*section.*type="neon-neume-line".*/)) {
+            if (!/<section\b[^>]*\btype="neon-neume-line"[^>]*>/.test(data)) {
               data = convertToVerovio(data);
             }