enable livereload for development

Gemfile

@@ -3,6 +3,7 @@
 source 'https://rubygems.org'
 
 gem 'middleman-gh-pages'
+gem 'middleman-livereload'
 
 # For faster file watcher updates on Windows:
 gem 'wdm', '~> 0.1.0', platforms: [:mswin, :mingw]

Gemfile.lock

@@ -44,9 +44,13 @@ GEM
     concurrent-ruby (1.0.5)
     contracts (0.13.0)
     dotenv (2.2.1)
+    em-websocket (0.5.1)
+      eventmachine (>= 0.12.9)
+      http_parser.rb (~> 0.6.0)
     erubis (2.7.0)
     ethon (0.10.1)
       ffi (>= 1.3.0)
+    eventmachine (1.2.3)
     execjs (2.7.0)
     fast_blank (1.0.0)
     fastimage (2.1.0)
@@ -66,6 +70,7 @@ GEM
       parallel (~> 1.3)
       typhoeus (~> 0.7)
       yell (~> 2.0)
+    http_parser.rb (0.6.0)
     i18n (0.7.0)
     kramdown (1.14.0)
     libv8 (5.3.332.38.5)
@@ -109,6 +114,10 @@ GEM
       uglifier (~> 3.0)
     middleman-gh-pages (0.3.1)
       rake (> 0.9.3)
+    middleman-livereload (3.4.6)
+      em-websocket (~> 0.5.1)
+      middleman-core (>= 3.3)
+      rack-livereload (~> 0.3.15)
     middleman-syntax (3.0.0)
       middleman-core (>= 3.2)
       rouge (~> 2.0)
@@ -128,6 +137,8 @@ GEM
     parallel (1.11.2)
     public_suffix (2.0.5)
     rack (2.0.3)
+    rack-livereload (0.3.16)
+      rack
     rake (12.0.0)
     rb-fsevent (0.10.2)
     rb-inotify (0.9.10)
@@ -159,6 +170,7 @@ DEPENDENCIES
   html-proofer
   middleman (>= 4.0.0)
   middleman-gh-pages
+  middleman-livereload
   middleman-navtree!
   middleman-syntax
   mini_racer

config.rb

@@ -7,6 +7,7 @@
 set :latest_release, '2017.6'
 set :min_ruby_version, '2.1'
 set :markdown, parse_block_html: true
+activate :livereload
 activate :relative_assets
 activate :navtree do |options|
     options.data_file = 'tree.yml' # The data file where our navtree is stored.