Bump kramdown and github-pages (RoboticsKnowledgebase#103)

Bumps [kramdown](https://github.com/gettalong/kramdown) and [github-pages](https://github.com/github/pages-gem). These dependencies needed to be updated together.

Updates `kramdown` from 2.3.0 to 2.3.1
- [Release notes](https://github.com/gettalong/kramdown/releases)
- [Changelog](https://github.com/gettalong/kramdown/blob/master/doc/news.page)
- [Commits](https://github.com/gettalong/kramdown/commits)

Updates `github-pages` from 213 to 214
- [Release notes](https://github.com/github/pages-gem/releases)
- [Commits](github/pages-gem@v213...v214)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Gemfile

@@ -1,6 +1,6 @@
 source "https://rubygems.org"
 
-gem "github-pages", "~> 213", group: :jekyll_plugins
+gem "github-pages", "~> 214", group: :jekyll_plugins
 
 group :jekyll_plugins do
   gem "jekyll-paginate"

Gemfile.lock

@@ -1,7 +1,7 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (6.0.3.6)
+    activesupport (6.0.3.7)
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (>= 0.7, < 2)
       minitest (~> 5.1)
@@ -22,19 +22,23 @@ GEM
     em-websocket (0.5.2)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0.6.0)
-    ethon (0.12.0)
-      ffi (>= 1.3.0)
+    ethon (0.14.0)
+      ffi (>= 1.15.0)
     eventmachine (1.2.7)
-    execjs (2.7.0)
-    faraday (1.3.0)
+    execjs (2.8.1)
+    faraday (1.4.1)
+      faraday-excon (~> 1.1)
       faraday-net_http (~> 1.0)
+      faraday-net_http_persistent (~> 1.1)
       multipart-post (>= 1.2, < 3)
-      ruby2_keywords
+      ruby2_keywords (>= 0.0.4)
+    faraday-excon (1.1.0)
     faraday-net_http (1.0.1)
+    faraday-net_http_persistent (1.1.0)
     ffi (1.15.0)
     forwardable-extended (2.6.0)
     gemoji (3.0.1)
-    github-pages (213)
+    github-pages (214)
       github-pages-health-check (= 1.17.0)
       jekyll (= 3.9.0)
       jekyll-avatar (= 0.7.0)
@@ -70,7 +74,7 @@ GEM
       jekyll-theme-time-machine (= 0.1.1)
       jekyll-titles-from-headings (= 0.5.3)
       jemoji (= 0.12.0)
-      kramdown (= 2.3.0)
+      kramdown (= 2.3.1)
       kramdown-parser-gfm (= 1.1.0)
       liquid (= 4.0.3)
       mercenary (~> 0.3)
@@ -198,12 +202,12 @@ GEM
       gemoji (~> 3.0)
       html-pipeline (~> 2.2)
       jekyll (>= 3.0, < 5.0)
-    kramdown (2.3.0)
+    kramdown (2.3.1)
       rexml
     kramdown-parser-gfm (1.1.0)
       kramdown (~> 2.0)
     liquid (4.0.3)
-    listen (3.5.0)
+    listen (3.5.1)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
     mercenary (0.3.6)
@@ -224,14 +228,14 @@ GEM
     nokogiri (1.11.4)
       mini_portile2 (~> 2.5.0)
       racc (~> 1.4)
-    octokit (4.20.0)
+    octokit (4.21.0)
       faraday (>= 0.9)
       sawyer (~> 0.8.0, >= 0.5.3)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
     public_suffix (4.0.6)
     racc (1.5.2)
-    rb-fsevent (0.10.4)
+    rb-fsevent (0.11.0)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
     rexml (3.2.5)
@@ -242,6 +246,10 @@ GEM
     rubyzip (2.3.0)
     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)
+      rb-inotify (~> 0.9, >= 0.9.7)
     sawyer (0.8.2)
       addressable (>= 2.3.5)
       faraday (> 0.8, < 2.0)
@@ -264,7 +272,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
-  github-pages (~> 213)
+  github-pages (~> 214)
   jekyll-feed
   jekyll-gist
   jekyll-paginate