Remark and rehype plugins (#562)

* remark plugins

* remove unused dependency

* enable codeblocks

* backward compatibility with remark-code-titles

* add support for rehype plugins

* add proper types for plugins

* fixes after review

- connect plugins by name
- make plugins configurable
- connect gfm and footnotes if no plugins provided from config
- add more plugins to example

* update and rename example

* add documentation for markdown plugins

* chore: rename with-markdown-plugins example

* chore: restructure dependencies

* feat: add back smartypants, fix mdx expressions

* chore: remove log

* test: add markdown plugin tests

* chore: add changeset

* docs: update markdown doc

Co-authored-by: Nate Moore <nate@skypack.dev>

1 files changed, 3 insertions, 1 deletions

diff --git a/packages/markdown-support/src/rehype-collect-headers.ts b/packages/markdown-support/src/rehype-collect-headers.ts
index edfcd29bc..de9b78692 100644
--- a/packages/markdown-support/src/rehype-collect-headers.ts
+++ b/packages/markdown-support/src/rehype-collect-headers.ts
@@ -14,11 +14,13 @@ export default function createCollectHeaders() {
     depth = Number.parseInt(depth);
 
     let text = '';
+
     visit(node, 'text', (child) => {
       text += child.value;
     });
 
-    let slug = slugger.slug(text);
+    let slug = node.properties.id || slugger.slug(text);
+
     node.properties = node.properties || {};
     node.properties.id = slug;
     headers.push({ depth, slug, text });