Bump redcarpet from 3.5.0 to 3.5.1

Bumps [redcarpet](https://github.com/vmg/redcarpet) from 3.5.0 to 3.5.1.
- [Release notes](https://github.com/vmg/redcarpet/releases)
- [Changelog](https://github.com/vmg/redcarpet/blob/master/CHANGELOG.md)
- [Commits](https://github.com/vmg/redcarpet/compare/v3.5.0...v3.5.1)

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

Gemfile.lock

@@ -6,7 +6,7 @@ GEM
     json (2.3.0)
     rake (13.0.1)
     rdoc (6.2.1)
-    redcarpet (3.5.0)
+    redcarpet (3.5.1)
     rspec (3.9.0)
       rspec-core (~> 3.9.0)
       rspec-expectations (~> 3.9.0)