Option to change log format to JSON

First off, thank you for putting in the work. This is a super helpful project.

I would appreciate it if it was possible to enable an option besides LOG_WITHOUT_NEWLINE and DISABLE_REQUEST_LOGS to have one line per request in the log output formatted as JSON.

One of the reasons is that I don't use the logs on the host machine directly. They might get scraped and processed out of order by Loki, so they might not end up next to each other. The second reason is that it would be simpler to parse them when they had the same format.

まず、既存の LOG_WITHOUT_NEWLINE と DISABLE_REQUEST_LOGS オプションを見つけ、request のログ記録経路を追跡します。request ごとに 1 行を出力する選択可能な JSON 形式を追加し、その後、出力を一貫してパースでき、要求されたログ情報が保持されることを確認します。