How do I serve a Jekyll site locally with Grunt BrowserSync and watch for Sass and Jekyll changes?

Question

I am trying to get a boilerplate template setup using Grunt, BrowsersSync, Jekyll and Sass.

I have been working on and off of this for a couple of days and there is always a tripping point. I am hoping someone has some experience with this and can point me in the right direction.

I am not to picky on particular plugins, its more about the desired outcome being as expected.

I want to runt the grunt task and it serve the site using BrowserSync then watch for changes on Sass and Jekyll related files, if something changes, update the browser.

I am working on a Windows machine which may make a difference as I have seen this done a lot with grunt-shell.

The current code is as follows:

'use strict';

module.exports = function (grunt) {

  grunt.initConfig({

    pkg: grunt.file.readJSON('package.json'),

    // Grunt Jekyll
    jekyll: {
      build: {
        dest: "_site"
      }
    },

    // Grunt Sass
    sass: {
      options: {
        sourceMap: true
      },
      dist: {
        files: {
          'dist/css/style.css': 'scss/index.scss'
        }
      }
    },

    // Grunt Contrib Watch
    watch: {
      sass: {
        files: ['scss/**/**/*.scss'],
        tasks: ['sass']
      },
      jekyll: {
        files: ['**/*.html', '**/**/*.md', 'dist/css/*.css'],
        tasks: ['jekyll']
      }
    },

    // Grunt BrowserSync
    browserSync: {
      dev: {
        bsFiles: {
          src: ['_site/dist/css/style.css', '_site/**/*.html']
        },
        options: {
          watchTask: true,
          server: '_site'
        }
      }
    }

  });

  // Load Grunt Plugins
  grunt.loadNpmTasks('grunt-contrib-watch');
  grunt.loadNpmTasks('grunt-jekyll');
  grunt.loadNpmTasks('grunt-sass');
  grunt.loadNpmTasks('grunt-browser-sync');


  // Register Tasks
  grunt.registerTask('build', ['sass', 'jekyll']);
  grunt.registerTask('default', ['build', 'browserSync', 'watch']);

};

I am no expert with Grunt so please go easy if there is something completely wrong.

Thanks for looking...