Updating from 1.15 to 1.16
If you are looking to update from 1.16 to a newer version, check out these tutorials. They have much more detailed information.
Changes​
The main difference between 1.15 and 1.16 is that a lot of the world gen code moved to data packs. Instead of simply extending classes like Biome, Dimension, etc, they are loaded dynamically from json files.
This page is a stub. If you would like to add specific instructions to update a mod to 1.16, please contact me!