chore: use the 'es' format name
chore: use the 'es' format name

'es6' was renamed to 'es'

alangpierce/decaffeinate,eventualbuddha/decaffeinate,alangpierce/decaffeinate,alangpierce/decaffeinate,eventualbuddha/decaffeinate,decaffeinate/decaffeinate,decaffeinate/decaffeinate