I found that you could create custom start systems (like the sol system) in
Stellaris\common\solar_system_initializers\prescripted_species_systems
The file is pretty much self-explanatory and most things are easy to understand or to check by trial and error. However, I tried to find a way to add resources (e.g. +2 minerals) for mining/research stations and didn't find anything useful. Is it even possible to add specific boni to preset planets/moons so they are always there and not random?
Stellaris\common\solar_system_initializers\prescripted_species_systems
The file is pretty much self-explanatory and most things are easy to understand or to check by trial and error. However, I tried to find a way to add resources (e.g. +2 minerals) for mining/research stations and didn't find anything useful. Is it even possible to add specific boni to preset planets/moons so they are always there and not random?