[references] Add tabsets among the flag for HTML features

[cderv]

When settings minimal: true, some features can be re-enabled as mentioned in documentation https://quarto.org/docs/output-formats/html-basics.html#minimal-html

Tabsets is among those.

However it was not documented in our references because not in schema.

This PR adds this

YAML header example:

---
title: test
format: html
minimal: true
tabsets: true
---

For reference, those features that are disable are here in the code

quarto-cli/src/format/html/format-html.ts

Lines 608 to 623 in e09ae92

	function htmlFormatFeatureDefaults(
	format: Format,
	): HtmlFormatFeatureDefaults {
	const bootstrap = formatHasBootstrap(format);
	const minimal = format.metadata[kMinimal] === true;
	return {
	tabby: !minimal && !bootstrap,
	copyCode: !minimal,
	anchors: !minimal,
	hoverCitations: !minimal,
	hoverFootnotes: !minimal,
	figResponsive: !minimal,
	codeAnnotations: !minimal,
	hoverXrefs: !minimal,
	};
	}

And can be renable individually

quarto-cli/src/format/html/format-html.ts

Lines 246 to 290 in e09ae92

	// apply defaults
	if (featureDefaults.tabby) {
	options.tabby = format.metadata[kTabsets] !== false;
	} else {
	options.tabby = format.metadata[kTabsets] || false;
	}
	if (featureDefaults.copyCode) {
	options.copyCode = format.metadata[kCodeCopy] !== false;
	} else {
	options.copyCode = format.metadata[kCodeCopy] || false;
	}
	if (featureDefaults.anchors) {
	options.anchors = format.metadata[kAnchorSections] !== false;
	} else {
	options.anchors = format.metadata[kAnchorSections] || false;
	}
	if (featureDefaults.hoverCitations) {
	options.hoverCitations = format.metadata[kCitationsHover] !== false;
	} else {
	options.hoverCitations = format.metadata[kCitationsHover] || false;
	}
	if (featureDefaults.hoverFootnotes) {
	options.hoverFootnotes = format.metadata[kFootnotesHover] !== false;
	} else {
	options.hoverFootnotes = format.metadata[kFootnotesHover] || false;
	}
	// Books don't currently support hover xrefs (since the content to preview in the xref
	// is likely to be on another page and we don't want to do a full fetch of that page
	// to get the preview)
	if (featureDefaults.hoverXrefs) {
	options.hoverXrefs = format.metadata[kXrefsHover] !== false;
	} else {
	options.hoverXrefs = format.metadata[kXrefsHover] || false;
	}
	if (featureDefaults.figResponsive) {
	options.figResponsive = format.metadata[kFigResponsive] !== false;
	} else {
	options.figResponsive = format.metadata[kFigResponsive] || false;
	}
	if (featureDefaults.codeAnnotations) {
	options.codeAnnotations = format.metadata[kCodeAnnotations] || true;
	} else {
	options.codeAnnotations = format.metadata[kCodeAnnotations] || false;
	}

[cscheid]

(Sorry I missed this earlier) Changelog entry?

[cderv]

This is not a new feature, it was just no showing in the reference page and autocompletion. But it was already available.
Do we add changelog for YAML schema updates or fix ?

I definitely can, just didn't think it was needed.

[cscheid]

Do we add changelog for YAML schema updates or fix ?

Yes, because it affects (eg) quarto.org, yaml completions, yaml validation, etc.

[cderv]

Ok. I'll remember for next time (and so add for this one).

Thanks for the reminder !