Include attachments when parsing numbered lists

We currently process numbered lists in a two step process:

1. create the list itself
2. parse each line within the list through govspeak again

In the second step, govspeak has no knowledge of the attachments as we
weren't including this information.

Therefore adding in the attachment data, so govspeak can include these
inline.

CHANGELOG.md

@@ -1,3 +1,7 @@
+## Unreleased
+
+* Allow attachment links wtihin numbered lists ([#283](https://github.com/alphagov/govspeak/pull/283))
+
 ## 8.0.1
 
 * Add margin-bottom to embedded attachments ([#281](https://github.com/alphagov/govspeak/pull/281))

lib/govspeak.rb

@@ -380,7 +380,7 @@ def render_image(image)
 
     extension("numbered list", /^[ \t]*((s\d+\.\s.*(?:\n|$))+)/) do |body|
       body.gsub!(/s(\d+)\.\s(.*)(?:\n|$)/) do
-        "<li>#{Govspeak::Document.new(Regexp.last_match(2).strip).to_html}</li>\n"
+        "<li>#{Govspeak::Document.new(Regexp.last_match(2).strip, attachments: attachments).to_html}</li>\n"
       end
       %(<ol class="steps">\n#{body}</ol>)
     end