Fix goldmark toc rendering

Previously gordmark-based TOC renderes only `KindText` and `KindString`

This commit expands target node with Goldmark's renderer

I am not sure of what are expected results as TOC contents in some (rare) cases
but Blackfriday's behaviours are fundamentally respected.

For example,
- image `[image text](link)` is rendered as `<img>` tag
- GFM AutoLink `gohugo.io` is rendered as text

* Render AutoLink as <a> tag as Blackfriday does

Fixes #6736
Fixes #6809

markup/goldmark/convert.go

@@ -81,15 +81,7 @@ func (c *goldmarkConverter) SanitizeAnchorName(s string) string {
 func newMarkdown(pcfg converter.ProviderConfig) goldmark.Markdown {
 	mcfg := pcfg.MarkupConfig
 	cfg := pcfg.MarkupConfig.Goldmark
-
-	var (
-		extensions = []goldmark.Extender{
-			newLinks(),
-			newTocExtension(),
-		}
-		rendererOptions []renderer.Option
-		parserOptions   []parser.Option
-	)
+	var rendererOptions []renderer.Option
 
 	if cfg.Renderer.HardWraps {
 		rendererOptions = append(rendererOptions, html.WithHardWraps())
@@ -103,6 +95,14 @@ func newMarkdown(pcfg converter.ProviderConfig) goldmark.Markdown {
 		rendererOptions = append(rendererOptions, html.WithUnsafe())
 	}
 
+	var (
+		extensions = []goldmark.Extender{
+			newLinks(),
+			newTocExtension(rendererOptions),
+		}
+		parserOptions []parser.Option
+	)
+
 	if mcfg.Highlight.CodeFences {
 		extensions = append(extensions, newHighlighting(mcfg.Highlight))
 	}