Adds CommitDescriptionRenderer

app/controllers/concerns/renders_commit_description.rb

+module RendersCommitDescription
+  def prepare_commit_descriptions_for_rendering(commit_descriptions)
+    Banzai::CommitDescriptionRenderer.render(commit_descriptions, @project, current_user)
+
+    commit_descriptions
+  end
+end

lib/banzai/commit_description_renderer.rb

+module Banzai
+  module CommitDescriptionRenderer
+    def self.render(commit_descriptions, project, user = nil)
+      ObjectRenderer.new(project, user).render(commit_descriptions, :commit_description)
+    end
+  end
+end