Add LaTeX defaults for renderers produced by options tableAttributes and bracketedSpans

[Witiko]

Closes #525.

[Witiko]

In addition to the LaTeX defaults for renderers produced by option tableAttributes, as shown in #525 (comment), this PR also adds LaTeX defaults for renderers produced by option bracketedSpans:

\documentclass{article}
\usepackage[
  bracketed_spans,
  relative_references,
  start_number = false,
]{markdown}
\begin{document}
\begin{markdown}

Demonstration of *bracketed spans* syntax:

 1. First item
 2. [Second item]{#second-item}
 3. Third item

Demonstration of a *relative reference*: See item <#second-item>.

\end{markdown}
\end{document}

[Witiko]

[T]his PR also adds LaTeX defaults for renderers produced by option bracketedSpans: [...]

As discussed with @MacLotsen at TUG 2024 and with @TeXhackse at matrix.org.