fix: update redcarpet requirement from 3.5.1 to 3.6.0

Updates the requirements on [redcarpet](https://github.com/vmg/redcarpet) to permit the latest version.
- [Release notes](https://github.com/vmg/redcarpet/releases)
- [Changelog](https://github.com/vmg/redcarpet/blob/master/CHANGELOG.md)
- [Commits](vmg/redcarpet@v3.5.1...v3.6.0)

---
updated-dependencies:
- dependency-name: redcarpet
  dependency-type: direct:production
...

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

Author: dependabot[bot]

Gemfile

@@ -7,5 +7,5 @@ gem "commonmarker", "=0.21.0"
 gem "creole", "=0.5.0"
 gem "org-ruby", "=0.9.12"
 gem "rdoc", "6.3.2"
-gem "redcarpet", "3.5.1"
+gem "redcarpet", "3.6.0"
 gem "wikicloth", "=0.8.3"