Add support for custom `bukkit.yml` file location

[1ntent1on]

/mv version -p output

https://paste.gg/p/anonymous/bb79cb85516c4faca9edaffc768a9629

Server logs

Server Version

Pufferfish version git-Pufferfish-24 (MC: 1.19)

Bug Description

Hello, im getting this warn on server startup "[Multiverse-Core] Could not read 'bukkit.yml'. Any Default worldgenerators will not be loaded!".
Its being caused by this JVM flag --bukkit-settings=config/bukkit.yml, which moves bukkit.yml info config folder (its useful for 1.19 servers because of the Paper config location changes)

Steps to reproduce

1. Create a config folder in your main directory
2. Move bukkit.yml into this new folder (remove the old default one)
3. Add this JVM startup flag --bukkit-settings=config/bukkit.yml
4. Start the server, wait for the warn message to appear

Agreements

• I have searched for and ensured there isn't already an open or resolved issue(s) regarding this.
• I was able to reproduce my issue on a freshly setup and up-to-date server with the latest version of Multiverse plugins with no other plugins and with no kinds of other server or client mods.