Bump kramdown from 2.3.0 to 2.3.1

Bumps [kramdown](https://github.com/gettalong/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)

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

Gemfile.lock

@@ -33,7 +33,7 @@ GEM
       sassc (> 2.0.1, < 3.0)
     jekyll-watch (2.2.1)
       listen (~> 3.0)
-    kramdown (2.3.0)
+    kramdown (2.3.1)
       rexml
     kramdown-parser-gfm (1.1.0)
       kramdown (~> 2.0)
@@ -48,7 +48,6 @@ GEM
     rb-fsevent (0.10.4)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
-    redcarpet (3.5.1)
     rexml (3.2.4)
     rouge (3.26.0)
     safe_yaml (1.0.5)
@@ -65,7 +64,6 @@ DEPENDENCIES
   jekyll
   jekyll-watch
   kramdown
-  redcarpet
   rouge
 
 BUNDLED WITH