Initial release.

• Fetches and applies the skin of Bedrock players from the GeyserMC Global API shortly after they join, with a few retries if it fails
• Players linked to a Java Edition account are skipped
• /skinfix [player] lets OPs re-fetch a skin (also from the console)
• Requests run asynchronously, so the server's TPS is not affected
• Messages in English (default) and Japanese (language: ja in config.yml)