Ignore generated assets in the repo and fix CI

[drewcassidy]

The generated assets in the git repo are all entirely generated by the java files. This seems to be confusing some people and makes it possible for the data to get out of sync with the source

Removing the generated files means that building requires running datagen, which is a pretty quick process. I've also added it as a step to the CI, so the datagen also gets tested

I also fixed the CI not uploading the correct jars :)

[MrRedstoneToGo]

So, you deleted (or had them deleted) the files in the src/generated folder on github so that there are no misunderstandings again, right? So, as far as I understand it, many recipes are only generated when you run the mod in Minecraft. And what does "CI" mean?

[Peruibeloko]

@MrRedstoneToGo The recipes are still generated, but not when the mod is run in game, its part of the process used to create the .jar file of the mod itself

CI stands for Continuous Integration, its a software development process in which updates to the source code automatically generate a build, instead of manually :)