add updated gemfile and purgecss

Author: nicholasphair

Gemfile

@@ -1,28 +1,38 @@
 source 'https://rubygems.org'
+
+gem 'jekyll'
+
+# Core plugins that directly affect site building
 group :jekyll_plugins do
-    gem "jekyll-remote-theme"
-    gem 'classifier-reborn'
-    gem 'jekyll'
     gem 'jekyll-archives'
-    gem 'jekyll-diagrams'
     gem 'jekyll-email-protect'
     gem 'jekyll-feed'
     gem 'jekyll-get-json'
     gem 'jekyll-imagemagick'
-    #gem 'jekyll-jupyter-notebook'
+    gem 'jekyll-jupyter-notebook'
     gem 'jekyll-link-attributes'
     gem 'jekyll-minifier'
     gem 'jekyll-paginate-v2'
+    gem 'jekyll-regex-replace'
     gem 'jekyll-scholar'
     gem 'jekyll-sitemap'
+    gem 'jekyll-tabs'
+    gem 'jekyll-terser', :git => "https://github.com/RobertoJBeltran/jekyll-terser.git"
     gem 'jekyll-toc'
     gem 'jekyll-twitter-plugin'
     gem 'jemoji'
-    gem 'mini_racer'
-    gem 'unicode_utils'
-    gem 'webrick'
+
+    gem 'classifier-reborn'  # used for content categorization during the build
 end
+
+# Gems for development or external data fetching (outside :jekyll_plugins)
 group :other_plugins do
+    gem 'css_parser'
     gem 'feedjira'
     gem 'httparty'
+    gem 'observer'       # used by jekyll-scholar
+    gem 'ostruct'        # used by jekyll-twitter-plugin
+    gem 'terser'         # used by jekyll-terser
+    # gem 'unicode_utils' -- should be already installed by jekyll
+    # gem 'webrick' -- should be already installed by jekyll
 end

purgecss.config.js

@@ -1,13 +1,6 @@
 module.exports = {
-    content: [
-        "_site/**/*.html",
-        "_site/**/*.js"
-    ],
-    css: [
-        "_site/assets/css/*.css"
-    ],
-    output: "_site/assets/css/",
-    skippedContentGlobs: [
-        "_site/assets/**/*.html"
-    ]
+  content: ["_site/**/*.html", "_site/**/*.js"],
+  css: ["_site/assets/css/*.css"],
+  output: "_site/assets/css/",
+  skippedContentGlobs: ["_site/assets/**/*.html"],
 };