Support GitHub-flavored Markdown

Gemfile

@@ -24,6 +24,7 @@ gem 'json_schemer'
 gem 'js-routes'
 gem 'jwt'
 gem 'kramdown'
+gem 'kramdown-parser-gfm'
 gem 'mimemagic'
 gem 'net-http-persistent'
 gem 'net-imap', require: false

Gemfile.lock

@@ -220,6 +220,8 @@ GEM
     kaminari-core (1.2.2)
     kramdown (2.4.0)
       rexml
+    kramdown-parser-gfm (1.1.0)
+      kramdown (~> 2.0)
     language_server-protocol (3.17.0.3)
     launchy (2.5.2)
       addressable (~> 2.8)
@@ -585,6 +587,7 @@ DEPENDENCIES
   json_schemer
   jwt
   kramdown
+  kramdown-parser-gfm
   letter_opener
   listen
   mimemagic

app/helpers/application_helper.rb

@@ -50,7 +50,7 @@ module ApplicationHelper
   end
 
   def render_markdown(markdown)
-    ActionController::Base.helpers.sanitize Kramdown::Document.new(markdown).to_html.strip
+    ActionController::Base.helpers.sanitize Kramdown::Document.new(markdown, input: 'GFM', hard_wrap: false).to_html.strip
   end
 
   def row(options = {}, &)