Markdown Filter removes a blank line separating sibling of a sub list item

[Kuro Kurosaka]

When Markdown filter extract and merges text like this:

1. List item 1:
   * List item 1 sub list 1 item 1

   List item 1 para 1

It removes the blank line, resulting:

1. List item 1:
   * List item 1 sub list 1 item 1
   List item 1 para 1

The resulting text is semantically different from the original text. Without a blank line, the line following is considered part of the leading line and concatenated as "List item 1 sub list item 1 List item 1 para 1".

Markdown needs to preserve the blank line in this case. (If there are more than one blank lines, they can be reduced to one blank line, on the other hand.)

[Kuro Kurosaka]

Fixing issue #814 by using the later version of flexMark (0.35.10) that fixes its bug causing this. Other adjustments were needed to absorbe minor differences in bheavior.

→ <<cset a597a6d9980e>>