docs: add prepare script to generate sidebar (#11894)

www/packages/docs-utils/src/sidebar-utils.ts

@@ -0,0 +1,7 @@
+import pkg from "slugify"
+const { default: slugify } = pkg
+
+export function getSectionId(path: string[]) {
+  path = path.map((p) => slugify(p.trim().toLowerCase()))
+  return path.join("_")
+}