Comment by darajava

Without a license your repo is technically not open-source, only source-available. A license says what people are allowed to do with the code, so if you don't add a license, they're not allowed to do anything.

Having a license clarifies what permissions are you giving to someone who downloads your code. The practical benefit is that others can clearly contribute back or build on your work without any legal concerns.

Something like MIT gives them permission to do anything as long as attribution is maintained, while avoiding liabilities.

But there are others you can pick: https://choosealicense.com/

Without a license, legaly nobody can do anything with the code. The license is essentially the way that you communicate what you will allow people to do with it.

For a project like this, I would strongly recommend an MIT license. That will essentially allow people to use the code and modify it, contribute back to it, and otherwise distribute their changes.