chore(deps): update dependency redcarpet to "~> 2.3.0"

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
redcarpet	"~> 2.2.2" → "~> 2.3.0"

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Release Notes

vmg/redcarpet (redcarpet)

v2.3.0

Compare Source

• Add a :disable_indented_code_blocks option Dmitriy Kiriyenko

• Fix issue #​57 Mike Morearty

• Ensure new lines characters are inserted when using the StripDown
  render. Robin Dupret

• Mark all symbols as hidden except the main entry point Tom Hughes

  This avoids conflicts with other gems that may have some of the
  same symbols, such as escape_utils which also uses houdini.

• Remove unnecessary function pointer Sam Soffes

• Add optional underline support Sam Soffes

  This is *italic* and this is _underline_ when enabled.

• Test that links with quotes work Michael Grosser

• Adding a prettyprint class for google-code-prettify Joel Rosenberg

• Remove unused C macros Matt Rogers

• Remove 'extern' definition for Init_redcarpet_rndr() Matt Rogers

• Remove Gemfile.lock from the gemspec Matt Rogers

• Removed extra unused test statement. Slipp D. Thompson

• Use test-unit gem to get some red/green output when running tests
  Michael Grosser

• Remove a deprecation warning and update Gemfile.lock Robin Dupret

• Added contributing file Brent Beer

• For tests for libxml2 > 2.8 strzibny

• SmartyPants: Preserve single backticks in HTML Mike Morearty

  When SmartyPants is processing HTML, single backticks should be left
  intact. Previously they were being deleted.

• Removed and ignored Gemfile.lock Ryan McGeary

• Added support for org-table syntax Ryan McGeary

  Adds support for using a plus (+) as an intersection character instead of
  requiring pipes (|). The emacs org-mode table syntax automatically manages
  ascii tables, but uses pluses for line intersections.

• Ignore /tmp directory Ryan McGeary

• Add redcarpet_ prefix for stack_* functions Kenta Murata

• Mark any html_attributes has held by a renderer as used Tom Hughes

• Add Rubinius to the list of tested implementations Gibheer

• Add a changelog file

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[aiuto]

I want to understand why and how we get this.

The 2.x branch is very old. There is a tag at the source repo for 2.2.2
https://github.com/vmg/redcarpet/tree/v2.2.2
but the one for 2.3.0 claims there is no commit there. https://github.com/vmg/redcarpet/tree/v2.3.0