Split parse and render for Goldmark

This also speeds up situations where you only need the fragments/toc and not the rendered content, e.g. Related
with fragments type indexing:

```bash

name            old time/op    new time/op    delta
RelatedSite-10    12.3ms ± 2%    10.7ms ± 1%  -12.95%  (p=0.029 n=4+4)

name            old alloc/op   new alloc/op   delta
RelatedSite-10    38.6MB ± 0%    38.2MB ± 0%   -1.08%  (p=0.029 n=4+4)

name            old allocs/op  new allocs/op  delta
RelatedSite-10      117k ± 0%      115k ± 0%   -1.36%  (p=0.029 n=4+4)
```

Fixes #10750

3 files changed, 25 insertions, 5 deletions

diff --git a/resources/page/page.go b/resources/page/page.go
index 00e716e83..84153b8c6 100644
--- a/resources/page/page.go
+++ b/resources/page/page.go
@@ -109,9 +109,13 @@ type ContentProvider interface {
 
 // ContentRenderer provides the content rendering methods for some content.
 type ContentRenderer interface {
-	// RenderContent renders the given content.
+	// ParseAndRenderContent renders the given content.
 	// For internal use only.
-	RenderContent(ctx context.Context, content []byte, renderTOC bool) (converter.Result, error)
+	ParseAndRenderContent(ctx context.Context, content []byte, enableTOC bool) (converter.ResultRender, error)
+	// For internal use only.
+	ParseContent(ctx context.Context, content []byte) (converter.ResultParse, bool, error)
+	// For internal use only.
+	RenderContent(ctx context.Context, content []byte, doc any) (converter.ResultRender, bool, error)
 }
 
 // FileProvider provides the source file.
diff --git a/resources/page/page_lazy_contentprovider.go b/resources/page/page_lazy_contentprovider.go
index e497718f9..d944b66d3 100644
--- a/resources/page/page_lazy_contentprovider.go
+++ b/resources/page/page_lazy_contentprovider.go
@@ -133,7 +133,16 @@ func (lcp *LazyContentProvider) TableOfContents(ctx context.Context) template.HT
 	return lcp.cp.TableOfContents(ctx)
 }
 
-func (lcp *LazyContentProvider) RenderContent(ctx context.Context, content []byte, renderTOC bool) (converter.Result, error) {
+func (lcp *LazyContentProvider) ParseAndRenderContent(ctx context.Context, content []byte, renderTOC bool) (converter.ResultRender, error) {
 	lcp.init.Do(ctx)
-	return lcp.cp.RenderContent(ctx, content, renderTOC)
+	return lcp.cp.ParseAndRenderContent(ctx, content, renderTOC)
+}
+
+func (lcp *LazyContentProvider) ParseContent(ctx context.Context, content []byte) (converter.ResultParse, bool, error) {
+	lcp.init.Do(ctx)
+	return lcp.cp.ParseContent(ctx, content)
+}
+func (lcp *LazyContentProvider) RenderContent(ctx context.Context, content []byte, doc any) (converter.ResultRender, bool, error) {
+	lcp.init.Do(ctx)
+	return lcp.cp.RenderContent(ctx, content, doc)
 }
diff --git a/resources/page/page_nop.go b/resources/page/page_nop.go
index 8946926a2..c04c019fe 100644
--- a/resources/page/page_nop.go
+++ b/resources/page/page_nop.go
@@ -538,7 +538,14 @@ func (p *nopPage) HeadingsFiltered(context.Context) tableofcontents.Headings {
 
 type nopContentRenderer int
 
-func (r *nopContentRenderer) RenderContent(ctx context.Context, content []byte, renderTOC bool) (converter.Result, error) {
+func (r *nopContentRenderer) ParseAndRenderContent(ctx context.Context, content []byte, renderTOC bool) (converter.ResultRender, error) {
 	b := &bytes.Buffer{}
 	return b, nil
 }
+
+func (r *nopContentRenderer) ParseContent(ctx context.Context, content []byte) (converter.ResultParse, bool, error) {
+	return nil, false, nil
+}
+func (r *nopContentRenderer) RenderContent(ctx context.Context, content []byte, doc any) (converter.ResultRender, bool, error) {
+	return nil, false, nil
+}