Modify Markdown `dl` syntax to support multiple subsequent `dt` or `dd` elements

Description

The current <dl> syntax (i.e. dt :: dd) only supports a 1:1 ratio of terms to descriptions.

Reference

• Original Discussion at Reddit
• The following examples follow the syntax set forth in Kramdown, Pandoc, MultiMarkdown, and Markdown Extra.

Basic Case:

First term
: First description
: Second description

<dl>
  <dt>First term</dt>
  <dd>First description</dd>
  <dd>Second description</dd>
</dl>

[develleoper]

@calculuschild Yeah, I noticed that the current implementation just uses bold tags and paragraph breaks, and honestly, that is good enough for users to reproduce 5e styles.

I totally understand the battle against syntax bloat, I’m just advocating for altering the current (unused?) <dl> support to better comply with the rest of the industry’s syntax and to allow for better support of the HTML spec on this tag. The tag is already in the system, it just doesn’t support the full feature set that it could, and uses its own unique syntax apart from the one on which other parsers seem to have standardized.

And @ericscheid, I don’t want to jump the gun, but will happily work up a PR, if that’s acceptable.

[ericscheid]

Two paragraphs in a <dd>, from #181

Two paragraphs in a definition of a term, from #181.

Though this is arguably an edge case, I am however all for semantic coding — it’s a rising tide that raises all boats.