Update dependency redcarpet to v3.6.1

Author: renovate[bot]

Gemfile.lock

@@ -89,7 +89,7 @@ GEM
     rb-fsevent (0.11.2)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
-    redcarpet (3.6.0)
+    redcarpet (3.6.1)
     reline (0.6.0)
       io-console (~> 0.5)
     rexml (3.3.9)