Feature Request: Support for Postmill‑based Websites (e.g., Raddle)

Feature Request: Support for Postmill‑based Websites (e.g., Raddle): a task in LegoFlow-SWE (Harbor dataset). Postmill is an open‑source link aggregator. The most popular instance is Raddle ( https://raddle.me/ ). We need extractors that allow gallery‑dl to download content from such sites.