I can't find the ComputerCraft.cfg that was in the original ComputerCraft mod.

Is there still a config file for this fork?

I tried adding a ComputerCraft.cfg to the config directory, to set 'turtlesNeedFuel' to false.

Is there a way to do this with this fork? If not, I suggest there should be a method for doing this.

Newer MC or forge changed how configs work, they are now toml files and server side stuff is now in the world folder.

As @Lupus590 mentioned, the location of configuration files has changed a bit in recent versions of ComputerCraft. See this bit of the wiki for where the new files are located.