Style/FormatStringToken should allow unnamed single formats

[marcandre]

I like the idea of that cop, but IIC, it wants me to change

format('%.2f', percentage)
# => into
format('%{percentage}.2f', percentage: percentage)

May I suggest that formatting a single parameter shouldn't require such verbosity? Or that there is at least an option to that effect? Current situation sounds to me like a cop that would enforce that all methods use only named parameters, even those with a single argument!

(Yes, I know, I can disable the cop for now...)

[noraj]

https://docs.rubocop.org/rubocop/0.88/cops_style.html#styleformatstringtoken

There is EnforcedStyle: unannotated but there is no EnabledForSingleParameter: false yet.

cc. @backus

[bbatsov]

Probably it'd be better if there was a config for the parameter count (e.g. 1,2,3) after which params should be named, but it's also a bit weird when to have special cases only for certain styles - they make the configuration harder to understand.