Bump jekyll from 3.8.3 to 3.8.4

Bumps [jekyll](https://github.com/jekyll/jekyll) from 3.8.3 to 3.8.4.
- [Release notes](https://github.com/jekyll/jekyll/releases)
- [Changelog](https://github.com/jekyll/jekyll/blob/master/History.markdown)
- [Commits](jekyll/jekyll@v3.8.3...v3.8.4)

Signed-off-by: dependabot[bot] <[email protected]>

Gemfile

@@ -1,6 +1,6 @@
 source "https://rubygems.org"
 
-gem "jekyll", "~> 3.8.3"
+gem "jekyll", "~> 3.8.4"
 gem "html-proofer", "~> 3.9.0"
 group :jekyll_plugins do
   gem "jekyll-feed", "~> 0.6"

Gemfile.lock

@@ -6,22 +6,22 @@ GEM
       i18n (>= 0.7, < 2)
       minitest (~> 5.1)
       tzinfo (~> 1.1)
-    addressable (2.5.2)
-      public_suffix (>= 2.0.2, < 4.0)
+    addressable (2.7.0)
+      public_suffix (>= 2.0.2, < 5.0)
     autoprefixer-rails (6.3.7)
       execjs
     backports (3.11.4)
     colorator (1.1.0)
     colorize (0.8.1)
-    concurrent-ruby (1.0.5)
-    em-websocket (0.5.1)
+    concurrent-ruby (1.1.7)
+    em-websocket (0.5.2)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0.6.0)
     ethon (0.11.0)
       ffi (>= 1.3.0)
     eventmachine (1.2.7)
     execjs (2.7.0)
-    ffi (1.9.25)
+    ffi (1.13.1)
     forwardable-extended (2.6.0)
     html-proofer (3.9.2)
       activesupport (>= 4.2, < 6.0)
@@ -35,7 +35,7 @@ GEM
     http_parser.rb (0.6.0)
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
-    jekyll (3.8.3)
+    jekyll (3.8.4)
       addressable (~> 2.4)
       colorator (~> 1.0)
       em-websocket (~> 0.5)
@@ -60,40 +60,40 @@ GEM
       jekyll (~> 3.3)
     jekyll-paginate-v2 (2.0.0)
       jekyll (~> 3.0)
+    jekyll-redirect-from (0.16.0)
+      jekyll (>= 3.3, < 5.0)
     jekyll-sass-converter (1.5.2)
       sass (~> 3.4)
-    jekyll-watch (2.0.0)
+    jekyll-watch (2.2.1)
       listen (~> 3.0)
     jekyll-youtube (1.0.0)
       jekyll
     kramdown (1.17.0)
-    liquid (4.0.0)
-    listen (3.1.5)
-      rb-fsevent (~> 0.9, >= 0.9.4)
-      rb-inotify (~> 0.9, >= 0.9.7)
-      ruby_dep (~> 1.2)
+    liquid (4.0.3)
+    listen (3.3.2)
+      rb-fsevent (~> 0.10, >= 0.10.3)
+      rb-inotify (~> 0.9, >= 0.9.10)
     mercenary (0.3.6)
     mini_portile2 (2.3.0)
     minitest (5.11.3)
     multi_json (1.13.1)
     nokogiri (1.8.4)
       mini_portile2 (~> 2.3.0)
     parallel (1.12.1)
-    pathutil (0.16.1)
+    pathutil (0.16.2)
       forwardable-extended (~> 2.6)
-    public_suffix (3.0.3)
+    public_suffix (4.0.6)
     rack (1.6.10)
     rack-protection (1.5.5)
       rack
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
-    rb-fsevent (0.10.3)
-    rb-inotify (0.9.10)
-      ffi (>= 0.5.0, < 2)
-    rouge (3.2.1)
-    ruby_dep (1.5.0)
-    safe_yaml (1.0.4)
-    sass (3.5.7)
+    rb-fsevent (0.10.4)
+    rb-inotify (0.10.1)
+      ffi (~> 1.0)
+    rouge (3.25.0)
+    safe_yaml (1.0.5)
+    sass (3.7.4)
       sass-listen (~> 4.0.0)
     sass-listen (4.0.0)
       rb-fsevent (~> 0.9, >= 0.9.4)
@@ -122,12 +122,13 @@ PLATFORMS
 
 DEPENDENCIES
   html-proofer (~> 3.9.0)
-  jekyll (~> 3.8.3)
+  jekyll (~> 3.8.4)
   jekyll-admin
   jekyll-analytics
   jekyll-autoprefixer
   jekyll-feed (~> 0.6)
   jekyll-paginate-v2
+  jekyll-redirect-from
   jekyll-youtube
   tzinfo-data