Add jekyll binstub

Make readme instructions more explicit
Exclude some files from build in sample configuration

Author: t-richards

README.md

@@ -1,18 +1,28 @@
-Magento Developer Documentation 
-=================================
+# Magento Developer Documentation
 
 Welcome! This site contains the latest Magento developer documentation for ongoing Magento 2.0 releases.
 
 To contribute, please fork the develop branch. We won't accept pull requests into master.
 
-**NEW!** You can now build this site yourself using Jekyll. Just rename `_config.devdocs.yml` to `_config.yml` and you're set. If you have questions, open an issue and ask us.
+# Building this site
 
-We're looking forward to hearing from you!
+You can build this site yourself using Jekyll. Here's how:
+
+```bash
+# Copy the sample config file and name it "config.yml"
+$ cp _config.devdocs.yml _config.yml
+
+# Install dependencies
+$ bundle install
+
+# Visit http://localhost:4000 in your favorite browser!
+$ bin/jekyll serve
+```
+
+If you have questions, open an issue and ask us. We're looking forward to hearing from you!
 
 *	<a href="https://twitter.com/MagentoDevDocs" class="twitter-follow-button" data-show-count="false">Follow @MagentoDevDocs</a>
-<script>!function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0],p=/^http:/.test(d.location)?'http':'https';if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src=p+'://platform.twitter.com/widgets.js';fjs.parentNode.insertBefore(js,fjs);}}(document, 'script', 'twitter-wjs');</script>
 
 *	<a href="mailto:[email protected]">E-mail us</a>
 
 *	<a href="http://devdocs.magento.com">Visit our documentation site</a>, built on GitHub using [Jekyll](http://jekyllrb.com/).
-

_config.devdocs.yml

@@ -30,3 +30,4 @@ gems:
 # Build settings
 markdown: kramdown
 highlighter: pygments
+exclude: [bin, _config.yml, Gemfile, Gemfile.lock, README.md]

bin/jekyll

@@ -0,0 +1,16 @@
+#!/usr/bin/env ruby
+#
+# This file was generated by Bundler.
+#
+# The application 'jekyll' is installed as part of a gem, and
+# this file is here to facilitate running it.
+#
+
+require 'pathname'
+ENV['BUNDLE_GEMFILE'] ||= File.expand_path("../../Gemfile",
+  Pathname.new(__FILE__).realpath)
+
+require 'rubygems'
+require 'bundler/setup'
+
+load Gem.bin_path('jekyll', 'jekyll')