View a list of things that need to be done over at TODO.md
Always write down any breaking changes inside CONVERSION_TUTORIAL.md
Use test.sh or test.cmd to test the project
For the most part, you just need to modify Cargo.toml and format_dependant.rs
There are other cases in the project (such as checking if ANY of the features is enabled in lib.rs) where you will need to add your new format's feature.
I would recommend just doing a search for "TOML" and adding your new format wherever the others are referenced