(PDOC-30) Fix Markdown parsing lists parsing

The transformer comment matching regex matched all whitespace after a comment.
Lines which were effectively "blank" and just had a comment would be erased.
Markdown lists need to end with a blank line. This messed up markdown
formatting.

The culprit is the regex /^\s*#\s/ which matches all of the comment ' #\n',
however we want to leave the newline alone for markdown to parse.
We replace the regex with /^\s*#[ \t]/ which will only match tabs or spaces
after the hash and leave our beloved newline alone.

lib/puppet_x/puppetlabs/strings/pops/yard_statement.rb

@@ -58,7 +58,7 @@ def extract_comments
         # FIXME: The gsub trims comments, but is extremely optimistic: It
         # assumes only one space separates the comment body from the
         # comment character.
-        comments.unshift line.gsub(/^\s*#\s/, '')
+        comments.unshift line.gsub(/^\s*#[ \t]/, '')
       else
         # No comment found on this line. We must be done piecing together a
         # comment block.