Modernize

[AntumDeluge]

• Removes references to deprecated minetest table/object & replaces with core.
• Adds ContentDB meta (.cdb.json).

I wasn't sure what to set dev_state to since it isn't listed on ContentDB, but I figured it was at least in MAINTENANCE_ONLY.

[OgelGames]

Probably don't need the .cdb.json, it just duplicates what's already set on ContentDB.

[wsor4035]

Probably don't need the .cdb.json, it just duplicates what's already set on ContentDB.

sigh, it doesnt duplicate, it controls from the .cdb.json.

[OgelGames]

You can include a .cdb.json file in the root of your content directory (ie: next to a .conf) to update the package meta.

It other words, it does nothing, because nothing needs updating.