Creating a Modpack
Creating a modpack is as simple as creating a subfolder in the mods directory. The same applies for addons.
Upon startup
When you start up the mod for the first time, a warning will typically be dispatched, asking you whether or not you want the engine to create the modpack's configuration file:
In most cases, you should allow the engine to generate the configuration file. This file is responsible for defining the metadata of your mod, as well as additional things, like Discord Rich Presence and state redirects. However, in certain cases, you may not want to have a configuration file at all, such as with testing.
There is also an option that should theoretically disable this popup right beside Developer Mode while keeping that state intact.