Discourse exists and is free to self-host and open source. Compared to classic forum software (like most *bb variants) it is a pleasure to use and feels not like a remnant of a lost age.
The (only?) downside is the similar name to Discord, but that’s not them to blame, because they had their name first.
This. If the file can be generated from the repository it should not be put inside it, but if you need it to build the project it should (unless it is an easy to install external dependency that should be declared in a Readme file).