Bump govuk-forms-markdown from 0.3.1 to 0.4.0

Bumps [govuk-forms-markdown](https://github.com/alphagov/govuk-forms-markdown) from 0.3.1 to 0.4.0.
- [Release notes](https://github.com/alphagov/govuk-forms-markdown/releases)
- [Changelog](https://github.com/alphagov/govuk-forms-markdown/blob/main/CHANGELOG.md)
- [Commits](alphagov/govuk-forms-markdown@8750474...ef476d0)

---
updated-dependencies:
- dependency-name: govuk-forms-markdown
  dependency-type: direct:production
...

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

Gemfile

@@ -45,7 +45,7 @@ gem "bootsnap", require: false
 # gem "rack-cors"
 
 # Our own custom markdown renderer
-gem "govuk-forms-markdown", github: "alphagov/govuk-forms-markdown", tag: "0.3.1"
+gem "govuk-forms-markdown", github: "alphagov/govuk-forms-markdown", tag: "0.4.0"
 
 # For structured logging
 gem "lograge"

Gemfile.lock

@@ -1,9 +1,9 @@
 GIT
   remote: https://github.com/alphagov/govuk-forms-markdown.git
-  revision: 87504748c303bf8bbd6383f3cbb06844fb38da73
-  tag: 0.3.1
+  revision: ef476d06e04678ddf6ad69bc983d12e34ba8f283
+  tag: 0.4.0
   specs:
-    govuk-forms-markdown (0.3.1)
+    govuk-forms-markdown (0.4.0)
       redcarpet (~> 3.6)
 
 GEM