diff --git a/Gemfile.lock b/Gemfile.lock
index fba448c..069b235 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,17 +1,22 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activemodel (4.2.9)
-      activesupport (= 4.2.9)
-      builder (~> 3.1)
-    activesupport (4.2.9)
-      i18n (~> 0.7)
+    Ascii85 (1.1.0)
+    activemodel (6.0.6.1)
+      activesupport (= 6.0.6.1)
+    activesupport (6.0.6.1)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 0.7, < 2)
       minitest (~> 5.1)
-      thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
-    addressable (2.7.0)
-      public_suffix (>= 2.0.2, < 5.0)
-    builder (3.2.4)
+      zeitwerk (~> 2.2, >= 2.2.2)
+    addressable (2.8.1)
+      public_suffix (>= 2.0.2, < 6.0)
+    afm (0.2.2)
+    async (2.3.1)
+      console (~> 1.10)
+      io-event (~> 1.1)
+      timers (~> 4.1)
     coffee-script (2.4.1)
       coffee-script-source
       execjs
@@ -20,18 +25,21 @@ GEM
     commonmarker (0.17.13)
       ruby-enum (~> 0.5)
     concurrent-ruby (1.1.7)
+    console (1.16.2)
+      fiber-local
     dnsruby (1.61.4)
       simpleidn (~> 0.1)
     em-websocket (0.5.1)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0.6.0)
-    ethon (0.12.0)
-      ffi (>= 1.3.0)
+    ethon (0.16.0)
+      ffi (>= 1.15.0)
     eventmachine (1.2.7)
     execjs (2.7.0)
     faraday (1.0.1)
       multipart-post (>= 1.2, < 3)
-    ffi (1.13.1)
+    ffi (1.15.5)
+    fiber-local (1.0.0)
     forwardable-extended (2.6.0)
     front_matter_parser (0.1.1)
     gemoji (3.0.1)
@@ -85,20 +93,23 @@ GEM
       octokit (~> 4.0)
       public_suffix (~> 3.0)
       typhoeus (~> 1.3)
+    hashery (2.1.2)
     html-pipeline (2.13.0)
       activesupport (>= 2)
       nokogiri (>= 1.4)
-    html-proofer (3.16.0)
+    html-proofer (5.0.4)
       addressable (~> 2.3)
-      mercenary (~> 0.3)
-      nokogumbo (~> 2.0)
-      parallel (~> 1.3)
+      async (~> 2.1)
+      nokogiri (~> 1.13)
+      pdf-reader (~> 2.11)
       rainbow (~> 3.0)
       typhoeus (~> 1.3)
       yell (~> 2.0)
+      zeitwerk (~> 2.5)
     http_parser.rb (0.6.0)
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
+    io-event (1.1.6)
     jekyll (3.9.0)
       addressable (~> 2.4)
       colorator (~> 1.0)
@@ -209,29 +220,34 @@ GEM
     kramdown-parser-gfm (1.1.0)
       kramdown (~> 2.0)
     liquid (4.0.3)
-    listen (3.2.1)
+    listen (3.8.0)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
     mercenary (0.3.6)
-    mini_portile2 (2.4.0)
+    mini_portile2 (2.8.1)
     minima (2.5.1)
       jekyll (>= 3.5, < 5.0)
       jekyll-feed (~> 0.9)
       jekyll-seo-tag (~> 2.1)
-    minitest (5.14.1)
+    minitest (5.17.0)
     multipart-post (2.1.1)
-    nokogiri (1.10.10)
-      mini_portile2 (~> 2.4.0)
-    nokogumbo (2.0.2)
-      nokogiri (~> 1.8, >= 1.8.4)
+    nokogiri (1.14.0)
+      mini_portile2 (~> 2.8.0)
+      racc (~> 1.4)
     octokit (4.18.0)
       faraday (>= 0.9)
       sawyer (~> 0.8.0, >= 0.5.3)
-    parallel (1.19.2)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
+    pdf-reader (2.11.0)
+      Ascii85 (~> 1.0)
+      afm (~> 0.2.1)
+      hashery (~> 2.0)
+      ruby-rc4
+      ttfunk
     public_suffix (3.1.1)
-    rainbow (3.0.0)
+    racc (1.6.2)
+    rainbow (3.1.1)
     rb-fsevent (0.10.4)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
@@ -239,7 +255,8 @@ GEM
     rouge (3.19.0)
     ruby-enum (0.8.0)
       i18n
-    rubyzip (2.3.0)
+    ruby-rc4 (0.1.5)
+    rubyzip (2.3.2)
     safe_yaml (1.0.5)
     sass (3.7.4)
       sass-listen (~> 4.0.0)
@@ -257,6 +274,8 @@ GEM
     terminal-table (1.8.0)
       unicode-display_width (~> 1.1, >= 1.1.1)
     thread_safe (0.3.6)
+    timers (4.3.5)
+    ttfunk (1.7.0)
     typhoeus (1.4.0)
       ethon (>= 0.9.0)
     tzinfo (1.2.7)
@@ -266,6 +285,7 @@ GEM
     unf_ext (0.0.7.7)
     unicode-display_width (1.7.0)
     yell (2.2.2)
+    zeitwerk (2.6.6)
 
 PLATFORMS
   ruby