use full `result` and `error` instead of `res` and `err`
use full `result` and `error` instead of `res` and `err`

Just to be a bit nicer

ArmorDarks/grunt-nunjucks-2-html,ArmorDarks/grunt-nunjucks-2-html,vitkarpov/grunt-nunjucks-2-html,vitkarpov/grunt-nunjucks-2-html