Go into the code and you'll see a bunch of defined blocks, such as "addItem" that perform that function for a list. You can use them so that your code can create, delete, and edit lists (instead of manually doing that). This lets you make projects where the user can create, delete, and edit lists for whatever function that serves in your project.
Credit me if you use this in your project. I made this for my own project, which is a programming language. One of its functions is using lists, so I needed to make this functionality. I decided to make this its own project so other people could use it for their own projects (it's not just useful for making programming languages; I can see a lot of other times where it would be useful).
