My goals for the open-source license is credit for contributions like I get credit for the code I write and I would like if a person shows me a concept of how to do something and I implement it I want him to get credit for showing me how I could do something, but he never showed any code, so the code I wrote for it is mine, but the idea/concept was his.
I would also like something where "I give you source code you give me your changes back." (quote from Linus Torvalds https://youtu.be/PaKIZ7gJlRU?t=24 24-45) I was thinking GNU General Public License v2.0 would satisfy these needs but would like more opinions on if this is the right choice.
The code will be written in a game called Garry's mod using the steam workshop add-on called wire mod. Within the add-on is an Expression 2 toll which is where the code is run and can be saved within the game to a txt file which later can be opened or copied from to rerun/run the code. I believe the add-on source code is available on GitHub under Apache 2.0.