index.js
function usage(gulp, options) {
    // re-define options if needed
    if (options) {
        Object.assign(OPTIONS, options);
    }

    return new Promise(function(resolve) {
        build(gulp);
        print();
        resolve();
    });
}
function usage(gulp, options) {
    // re-define options if needed
    if (options) {
        Object.assign(OPTIONS, options);
    }

    return new Promise(function(resolve) {
        build(gulp);
        print();
        resolve();
    });
}
Prints usage help information for the given gulp
instance.
Usually it is used as a task within gulpfile.js in your project
Please make sure all your comments are properly annotated

@examples
<caption>Typical usage:</caption>
var gulp = require('gulp');

gulp.task('help', => require('gulp-help-doc')(gulp));

@param {Gulp} gulp - gulp instance to analyze
@param {ConfigOptions} [options]
@returns {Promise}
@access public