World edit with scarpet.
To install and use, create a file called world-edit.sc, and copy paste code from world-edit.sc. Documentation and help can be found here, and there's also an in-game help menu.
For instructions on how to install scarpet scripts: https://github.com/gnembon/fabric-carpet/wiki/Installing-carpet-scripts-in-your-world
If you want to contribute, make sure you have read the contributions manual first. This is important to maintain the code structure and formatting, to make it easier for future contributions.
NB: It's good practice to read this before every contribution. This project is a fast-changing WIP, so the code structure and formalities may change, so they may not be the same since the last time you read.