I want to configure rubocop so it has no rules enabled and then create a list of the rules I do want enabled. I had a look a the rubocop docs but only found ways to disable individual rules.
If you're adding rubocop to an existing project a powerful soluion is to run
rubocop --auto-gen-config
This auto-generates a rubocop.todo.yml with all the current offending cops disabled with the most useful specificity. This way over time you can remove the disabled cops in the todo
file and incrementally improve your code quality as and when appropriate.