function build(options) {
    return documentation
        .build(options.files, {
            shallow: true,
            config: options.config
        })
        .then(function docsFormat(docs) {
            return documentation.formats.md(docs, {
                markdownToc: true
            });
        })
        .then(function docsWrite(docsContent) {
            var output = util.format(
                JEKYLL_HEADER_TEMPLATE,
                options.title,
                options.permalink,
                docsContent
            );

            fs.writeFileSync(options.output, output);
        });
}
@function build
@param {Object} options - Options
@param {Array} options.files - Array of file paths ["./foo.js"]
@param {String} options.config - Path to "config.yaml"
@param {String} options.output - Path to output dir
@param {String} options.title - Jekyll title
@param {String} options.permalink - Jekyll permalink
@returns {Promise} - Promise