Gruntfile.js

module.exports = function (grunt) {
    grunt.initConfig({
        shell: {
            jekyllBuild: {
                command: 'jekyll build --config _config.yml,_config_dev.yml'
            }
        },
        connect: {
            server: {
                options: {
                    port: 4000,
                    base: '_site'
                }
            }
        },
        watch: {
          livereload: {
            files: [
                '**/**',
                '!_site/**',
                '!**/node_modules/**'
            ],
            tasks: ['shell:jekyllBuild'],
            options: {
              livereload: true
            },
          },
        }
    });

    grunt.loadNpmTasks('grunt-contrib-connect');
    grunt.loadNpmTasks('grunt-contrib-watch');
    grunt.loadNpmTasks('grunt-shell');
    grunt.registerTask('default', ['shell', 'connect', 'watch'])
}