Add API documentation and underground station importer

- Introduced a new HTML documentation page for the oradio API, including a JavaScript file to handle dynamic content and API requests.
- Added a CSS file for styling the documentation page.
- Implemented an underground station importer script that fetches data from Radio-Browser and writes it to a JSON file.
- Created a stats module to compute and manage vote and play statistics for radio stations.
- Added a polyfill for modulepreload to ensure compatibility with older browsers.

server/scripts/report-streams.js

@@ -7,6 +7,6 @@ const rows = db.prepare(`
   ORDER BY (st.last_status = 'up'), s.name
 `).all();
 for (const r of rows) {
-  const tag = r.last_status === 'up' ? 'OK ' : 'BAD';
-  console.log(tag, (r.last_status || '').padEnd(14), r.format.padEnd(5), r.name, '->', r.url);
+    const tag = r.last_status === 'up' ? 'OK ' : 'BAD';
+    console.log(tag, (r.last_status || '').padEnd(14), r.format.padEnd(5), r.name, '->', r.url);
 }