Add Jekyll Minifier

Jekyll HTML/XML/CSS/JS Minifier utilising yui-compressor, and htmlcompressor

https://github.com/digitalsparky/jekyll-minifier

JEKYLL_ENV=production bundle exec jekyll serve

To switch part of your config settings depending on the environment, use the build command option, for example --config _config.yml,_config.dev.yml. Settings in later files override settings in earlier files.

Gemfile

@@ -1,6 +1,10 @@
 source 'https://rubygems.org'
 
-gem 'github-pages'
+gem 'github-pages', group: :jekyll_plugins
+
+group :jekyll_plugins do
+  gem 'jekyll-minifier'
+end
 
 group :scripts do 
   gem 'mgem' 

Gemfile.lock

@@ -18,6 +18,7 @@ GEM
     commonmarker (0.17.13)
       ruby-enum (~> 0.5)
     concurrent-ruby (1.1.7)
+    cssminify2 (2.0.1)
     dnsruby (1.61.4)
       simpleidn (~> 0.1)
     em-websocket (0.5.2)
@@ -87,6 +88,7 @@ GEM
     html-pipeline (2.14.0)
       activesupport (>= 2)
       nokogiri (>= 1.4)
+    htmlcompressor (0.4.0)
     http_parser.rb (0.6.0)
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
@@ -127,6 +129,12 @@ GEM
     jekyll-mentions (1.6.0)
       html-pipeline (~> 2.3)
       jekyll (>= 3.7, < 5.0)
+    jekyll-minifier (0.1.10)
+      cssminify2 (~> 2.0)
+      htmlcompressor (~> 0.4)
+      jekyll (>= 3.5)
+      json-minify (~> 0.0.3)
+      uglifier (~> 4.1)
     jekyll-optional-front-matter (0.3.2)
       jekyll (>= 3.0, < 5.0)
     jekyll-paginate (1.1.0)
@@ -196,6 +204,9 @@ GEM
       gemoji (~> 3.0)
       html-pipeline (~> 2.2)
       jekyll (>= 3.0, < 5.0)
+    json (2.5.1)
+    json-minify (0.0.3)
+      json (> 0)
     kramdown (2.3.0)
       rexml
     kramdown-parser-gfm (1.1.0)
@@ -248,6 +259,8 @@ GEM
       ethon (>= 0.9.0)
     tzinfo (1.2.7)
       thread_safe (~> 0.1)
+    uglifier (4.2.0)
+      execjs (>= 0.3.0, < 3)
     unf (0.1.4)
       unf_ext
     unf_ext (0.0.7.7)
@@ -266,6 +279,7 @@ PLATFORMS
 DEPENDENCIES
   git
   github-pages
+  jekyll-minifier
   mgem
   yard-coderay
   yard-mruby

_config.dev.yml

@@ -0,0 +1,2 @@
+jekyll-minifier:
+  exclude: "*"

_config.yml

@@ -11,6 +11,8 @@ highlighter: rouge
 url: https://mruby.org
 repository: https://github.com/mruby/mruby.github.io
 include: _index.html
+plugins:
+  - jekyll-minifier
 exclude:
   - CODEOWNERS
   - Gemfile