Bump kramdown from 1.17.0 to 2.1.0

Bumps [kramdown](https://github.com/gettalong/kramdown) from 1.17.0 to 2.1.0.
- [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@dependabot.com>

Gemfile

@@ -14,7 +14,7 @@ gem 'rails', '5.2.2' # Ruby on Rails MVC framework
 gem 'bootsnap', '>= 1.3', require: false # Optimize Rails boot time
 
 # TEXT PROCESSING
-gem 'kramdown', '~> 1.17' # Markdown <> HTML
+gem 'kramdown', '~> 2.1' # Markdown <> HTML
 gem 'loofah', '~> 2.2' # HTML sanitizer
 gem 'rinku', '~> 2.0.4' # Autolink
 

Gemfile.lock

@@ -498,7 +498,7 @@ GEM
       activerecord
       kaminari-core (= 1.1.1)
     kaminari-core (1.1.1)
-    kramdown (1.17.0)
+    kramdown (2.1.0)
     launchy (2.4.3)
       addressable (~> 2.3)
     letter_opener (1.7.0)
@@ -818,7 +818,7 @@ DEPENDENCIES
   inherited_resources (~> 1.9)
   jsonapi_helpers (~> 0.2)
   kaminari (~> 1.1)
-  kramdown (~> 1.17)
+  kramdown (~> 2.1)
   letter_opener (~> 1.7)
   listen (~> 3.1)
   lograge (~> 0.10)