Describe the feature

Example:
The Vanilla Tweaks 'Graves' datapack requires the keepInventory gamerule to be set to true in all dimensions. As the rule defaults to false, this requires walking the list of all dimensions and setting the rule individually when adding the datapack to an existing world.

How is the feature useful to all Multiverse users?

The ability to change a rule in all worlds with a single command would be a benefit for consistency and complexity to the admin.

Agreements

• I have searched for and ensured there isn't already an open issue regarding this.

Added in the MV5 branch, will be merged to master when the whole update is complete