update Gemfile

Gemfile

-# frozen_string_literal: true
-
 source "https://rubygems.org"
-gemspec
 
-group :jekyll_plugins do
-  gem "jekyll-feed", 
-      "~> 0.6"
 
+# Hello! This is where you manage which Jekyll version is used to run.
+# When you want to use a different version, change it below, save the
+# file and run `bundle install`. Run Jekyll with `bundle exec`, like so:
+#
+#     bundle exec jekyll serve
+#
+
+gem "jekyll", "~> 4.0"
+gem "bundler", "> 2.0"
+
+gem "minima", "~> 2.5"
+gem 'jekyll-theme-lcsb-default', '~> 0.3.15'
+
+# If you want to use GitHub Pages, remove the "gem "jekyll"" above and
+# uncomment the line below. To upgrade, run `bundle update github-pages`.
+# gem "github-pages", group: :jekyll_plugins
+
+# If you have any plugins, put them here!
+group :jekyll_plugins do 
   gem "jekyll-paginate-v2",
       "~> 3",
       :git => "https://github.com/LCSB-BioCore/jekyll-paginate-v2.git"
 
-  gem 'jekyll-theme-lcsb-frozen-components', 
-      '~> 0.0.2', 
-      :git => "https://git-r3lab.uni.lu/core-services/jekyll-theme-lcsb-frozen-components.git", 
-      :tag => "0.0.2"
+ gem "jekyll-feed", 
+     "~> 0.6"
+     
+gem 'jekyll-email-protect',
+     "~> 1.1"
+     
+ gem 'jekyll-theme-lcsb-frozen-components', 
+     '~> 0.0.2', 
+     :git => "https://git-r3lab.uni.lu/core-services/jekyll-theme-lcsb-frozen-components.git", 
+     :tag => "0.0.2"
+
 end
 
+# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
+gem "tzinfo-data", platforms: [:mingw, :mswin, :x64_mingw, :jruby]
+
+# Performance-booster for watching directories on Windows
+gem "wdm", "~> 0.1.1" if Gem.win_platform?