spread the demo's features across the pages that would carry them

notes-on-water had become a kitchen sink: every feature from the last eight
loops on one page, which demonstrates the engine and misrepresents the site.

Now each lands where a real site would put it. The text marks, the abbreviation,
authored <kbd> and the margin note go to writing/typography, which is already
the page about what the engine does to words. Icons and the grouped panels go to
pages/colophon, which is the page about the theme — install instructions are
what tabs are actually for. about gets a lone expando, the-flood gets a chapter
note, and notes-on-water keeps what it is really for: the include and its
namespaced footnotes, the gauge table, the glossary and a contents list over its
own headings.

Seven bundles carry features now instead of two, and the demo cases moved with
them, so each still names the page it proves.

internal/web/example_test.go

@@ -119,27 +119,30 @@ var exampleFeatures = []featureCase{
 	{what: "an include is parsed as Markdown, and its fragment has no page of its own", path: "/writing/notes-on-water/", code: 200,
 		expect: []string{`<h2 id="method">Method</h2>`, "<em>Emphasis and links survive</em>"}},
 	{what: "a fragment is not a bundle", path: "/writing/notes-on-water/_method/", code: 404},
-	{what: "authored HTML renders, because the site root is trusted", path: "/writing/notes-on-water/", code: 200,
+	{what: "notation marks become elements, and a single tilde is a subscript not a strike", path: "/writing/typography/", code: 200,
+		expect: []string{"H<sub>2</sub>O", "10<sup>-3</sup>", "<mark>second column</mark>", "<del>this phrase</del>"},
+		absent: []string{"<del>2</del>", "<sup>2 + y</sup>"}},
+	{what: "an abbreviation expands and its definition line renders nothing", path: "/writing/typography/", code: 200,
+		expect: []string{`<abbr title="Normalization Form C">NFC</abbr>`}, absent: []string{"*[NFC]"}},
+	{what: "authored HTML renders, because the site root is trusted", path: "/writing/typography/", code: 200,
 		expect: []string{"<kbd>Shift</kbd>"}, absent: []string{"raw HTML omitted"}},
-	{what: "notation marks become elements, and a single tilde is a subscript not a strike", path: "/writing/notes-on-water/", code: 200,
-		expect: []string{"H<sub>2</sub>O", "10<sup>-3</sup>", "<mark>important</mark>", "<del>a struck phrase</del>"},
-		absent: []string{"<del>2</del>"}},
-	{what: "an abbreviation expands and its definition line renders nothing", path: "/writing/notes-on-water/", code: 200,
-		expect: []string{`<abbr title="National Institute of Water and Atmospheric Research">NIWA</abbr>`},
-		absent: []string{"*[NIWA]"}},
-	{what: "panels and margin notes need no script", path: "/writing/notes-on-water/", code: 200,
-		expect: []string{"<summary>Show the raw transcription</summary>", `<details name="readings"`,
-			`<aside class="side">`, `<p class="side-title">On the gauges</p>`},
-		absent: []string{"<script"}},
-	{what: "a table of contents links the page's own headings", path: "/writing/notes-on-water/", code: 200,
-		expect: []string{`<nav class="toc">`, `<a href="#the-dialect">The dialect</a>`, `class="toc-2"`}},
+	{what: "a margin note is a container the theme places", path: "/writing/typography/", code: 200,
+		expect: []string{`<aside class="side">`, `<p class="side-title">On line breaking</p>`}},
+	{what: "an icon renders through the theme, and an unknown one keeps its text", path: "/pages/colophon/", code: 200,
+		expect: []string{"💡", ":nosuchicon:"}},
+	{what: "grouped panels are tabs, and need no script", path: "/pages/colophon/", code: 200,
+		expect: []string{`<details name="run" open>`, "<summary>Serve your own</summary>"}, absent: []string{"<script"}},
+	{what: "a lone panel is an expando", path: "/pages/about/", code: 200,
+		expect: []string{"<details>", "<summary>What is deliberately not shown</summary>"}},
+	{what: "an admonition renders inside a comic chapter too", path: "/comics/the-long-monsoon/the-flood/", code: 200,
+		expect: []string{`<aside class="admonition note">`, `<p class="admonition-title">On the timeline</p>`}},
+	{what: "the dialect renders tables and definition lists", path: "/writing/notes-on-water/", code: 200,
+		expect: []string{"<table>", "<th>Gauge</th>", "<dl>", "<dt>Monsoon</dt>"}},
 	{what: "a container renders its body through the theme fragment", path: "/writing/notes-on-water/", code: 200,
-		expect: []string{`<aside class="admonition warn">`, `<p class="admonition-title">Calibration</p>`,
-			"<em>emphasis</em>", "H<sub>2</sub>O"}, absent: []string{":::"}},
-	{what: "an icon renders through the theme, and prose colons are untouched", path: "/writing/notes-on-water/", code: 200,
-		expect: []string{"⚠️", ":nosuchicon:", "10:30:15", "key:value:pair"}},
-	{what: "the dialect renders tables, definition lists and strikethrough", path: "/writing/notes-on-water/", code: 200,
-		expect: []string{"<table>", "<th>Gauge</th>", "<dl>", "<dt>Monsoon</dt>", "<del>a struck phrase</del>"}},
+		expect: []string{`<aside class="admonition warn">`, `<p class="admonition-title">Calibration</p>`, "<em>emphasis</em>"},
+		absent: []string{":::"}},
+	{what: "a table of contents links the page's own headings", path: "/writing/notes-on-water/", code: 200,
+		expect: []string{`<nav class="toc">`, `<a href="#readings">Readings</a>`, `class="toc-2"`}},
 	{what: "a fragment's footnote ids are namespaced, so the page's own keep working", path: "/writing/notes-on-water/", code: 200,
 		expect: []string{`id="fn:1"`, `id="_method-fn:1"`, `href="#_method-fn:1"`}},
 	{what: "a page offers its extras only when it has them", path: "/writing/notes-on-water/", code: 200,