docs(table): document folding a record into column groups

[markdumay]

Summary

Documents wrap-cols on the Table component page, under Table wrapping.

Requires gethinode/hinode#2138, released in v3.23.0.

Why

The page documented folding the last column, which is not enough for a table with many columns — it still scrolls sideways on a phone, because the remaining columns are each narrow but there are too many of them. wrap-cols folds a record into groups so it stacks as a card instead.

What's added

A Column groups subsection with a live example (2,4,1 across seven columns), covering:

• what the counts mean, and that only the first group stays aligned down the table
• that later groups lay their values out in equal columns which drop to as many as fit the viewport
• the rule the counts must satisfy, and that a list left stale when a column is added is refused and falls back to wrapping the last column only
• that folded headings are hidden, so the values carry no label — which is what makes the grouping a decision the author makes rather than a default

The generated argument table at the bottom of the page picks wrap-cols up automatically from the structure definition.

Testing

Built through hinode's example site with this branch mounted in place of the released module. The example renders as a plain table, so it folds server-side: table-wrap table-wrap-3, three rows per record, with the values split into [Database, launch, Shipped, both] and the description.

markdownlint-cli2 reports 0 issues on the changed file.

Note on existing lint failures

pnpm lint fails on content/blocks/preview.md, content/blocks/testimonials.md and content/components/testimonial.md (MD060, MD012, MD009). Those are pre-existing on main and untouched here — content/components/table.md is the only changed file and lints clean.