cleanup, docs

site/doc/pages/file_mtime.txt

@@ -12,7 +12,5 @@ return value : Unix time stamp of the file's last modification
 :content
 Retrieves the last modification date of `file_name` as a Unix timestamp.
 
-## Related Concepts
-
-- PHP: `filemtime()`
-- JavaScript / Node.js: Node `fs.statSync().mtimeMs` or `fs.promises.stat()`
+:example
+print("file_mtime example\n");