Include autolink text in Markdown heading anchors

internal/validation/markdown_check_test.go

@@ -16,6 +16,8 @@ func TestCheckMarkdownLinksResolvesCommittedDestinationsAndFragments(t *testing.
 		"# Start\n" +
 		"[target](target.md?view=1#TARGET)\n" +
 		"[same](#START)\n" +
+		"[url heading](autolinks.md#httpsexampleinvalid)\n" +
+		"[email heading](autolinks.md#maintainerexampleinvalid)\n" +
 		"[top](#)\n" +
 		"[directory](assets/?view=1)\n" +
 		"[binary](image.bin#not-an-anchor)\n" +
@@ -26,6 +28,7 @@ func TestCheckMarkdownLinksResolvesCommittedDestinationsAndFragments(t *testing.
 	repository, tree := committedMarkdownTree(t, map[string][]byte{
 		"guide.md":        guide,
 		"target.md":       []byte("# Target\n"),
+		"autolinks.md":    []byte("# <https://example.invalid>\n# <maintainer@example.invalid>\n"),
 		"docs/a b.md":     []byte("# Café\n"),
 		"assets/file.md":  []byte("# Asset\n"),
 		"nested/guide.md": []byte("# Nested\n[same](#NESTED)\n[query](?view=1#nested)\n"),