start work on table of contents

src/plugins/rehype.js

@@ -4,7 +4,7 @@ import { toText } from 'hast-util-to-text';
 import { makeSlug } from '../lib/utils.js';
 
 
-export function localPlugins() {
+export function localRehype() {
     let printed = false;
 
     return (tree, vfile) => {

src/plugins/remark.js

@@ -0,0 +1,19 @@
+import { visit } from 'unist-util-visit';
+import { toString } from 'mdast-util-to-string';
+
+
+// build table of contents and inject into frontmatter
+export function localRemark() {
+    return (tree, vfile) => {
+        let toc = [];
+        
+        visit(tree, 'heading', node => {
+            toc.push({
+                text: toString(node),
+                depth: node.depth,
+            });
+        });
+
+        vfile.data.fm.toc = toc;
+    }
+}