diff --git a/Gemfile b/Gemfile
index 0d52acf..39a5c03 100644
--- a/Gemfile
+++ b/Gemfile
@@ -4,10 +4,12 @@
 source 'https://rubygems.org'
 
 group :development, :test do
-  gem 'jekyll', '~> 3.8.4'
+  gem 'jekyll', '~> 3.9.0'
   gem 'jekyll-redirect-from', '~> 0.13.0'
   gem 'jekyll-sitemap', '~> 1.2.0'
   gem 'redcarpet', '~> 3.4.0'
+  gem 'kramdown', '~> 2.3.0'
+  gem 'kramdown-parser-gfm', '~> 1.1.0'
   gem 'nokogiri', '~> 1.10.8'
   gem "jekyll-last-modified-at", "~> 1.0"
 end
diff --git a/Gemfile.lock b/Gemfile.lock
index 6948159..841a07e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -4,31 +4,31 @@ GEM
     addressable (2.7.0)
       public_suffix (>= 2.0.2, < 5.0)
     colorator (1.1.0)
-    concurrent-ruby (1.1.5)
+    concurrent-ruby (1.1.7)
     em-websocket (0.5.1)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0.6.0)
     eventmachine (1.2.7)
-    ffi (1.11.1)
+    ffi (1.13.1)
     forwardable-extended (2.6.0)
     http_parser.rb (0.6.0)
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
-    jekyll (3.8.4)
+    jekyll (3.9.0)
       addressable (~> 2.4)
       colorator (~> 1.0)
       em-websocket (~> 0.5)
       i18n (~> 0.7)
       jekyll-sass-converter (~> 1.0)
       jekyll-watch (~> 2.0)
-      kramdown (~> 1.14)
+      kramdown (>= 1.17, < 3)
       liquid (~> 4.0)
       mercenary (~> 0.3.3)
       pathutil (~> 0.9)
       rouge (>= 1.7, < 4)
       safe_yaml (~> 1.0)
-    jekyll-last-modified-at (1.0.1)
-      jekyll (~> 3.3)
+    jekyll-last-modified-at (1.3.0)
+      jekyll (>= 3.7, < 5.0)
       posix-spawn (~> 0.3.9)
     jekyll-redirect-from (0.13.0)
       jekyll (~> 3.3)
@@ -38,24 +38,28 @@ GEM
       jekyll (~> 3.3)
     jekyll-watch (2.2.1)
       listen (~> 3.0)
-    kramdown (1.17.0)
+    kramdown (2.3.0)
+      rexml
+    kramdown-parser-gfm (1.1.0)
+      kramdown (~> 2.0)
     liquid (4.0.3)
-    listen (3.2.0)
+    listen (3.2.1)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
     mercenary (0.3.6)
     mini_portile2 (2.4.0)
-    nokogiri (1.10.8)
+    nokogiri (1.10.10)
       mini_portile2 (~> 2.4.0)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
-    posix-spawn (0.3.13)
-    public_suffix (4.0.1)
-    rb-fsevent (0.10.3)
-    rb-inotify (0.10.0)
+    posix-spawn (0.3.15)
+    public_suffix (4.0.5)
+    rb-fsevent (0.10.4)
+    rb-inotify (0.10.1)
       ffi (~> 1.0)
     redcarpet (3.4.0)
-    rouge (3.12.0)
+    rexml (3.2.4)
+    rouge (3.21.0)
     safe_yaml (1.0.5)
     sass (3.7.4)
       sass-listen (~> 4.0.0)
@@ -67,10 +71,12 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
-  jekyll (~> 3.8.4)
+  jekyll (~> 3.9.0)
   jekyll-last-modified-at (~> 1.0)
   jekyll-redirect-from (~> 0.13.0)
   jekyll-sitemap (~> 1.2.0)
+  kramdown (~> 2.3.0)
+  kramdown-parser-gfm (~> 1.1.0)
   nokogiri (~> 1.10.8)
   redcarpet (~> 3.4.0)