fix: Paragraphs in table cells skipped in import

Port HTML importer rules from enterprise fork

server/utils/turndown/emptyLists.ts

@@ -0,0 +1,22 @@
+import TurndownService from "turndown";
+
+/**
+ * A turndown plugin for unwrapping top-level empty list items.
+ *
+ * @param turndownService The TurndownService instance.
+ */
+export default function emptyLists(turndownService: TurndownService) {
+  turndownService.addRule("empty-lists", {
+    filter(node) {
+      return (
+        node.nodeName === "LI" &&
+        node.childNodes.length === 1 &&
+        (node.firstChild?.nodeName === "OL" ||
+          node.firstChild?.nodeName === "UL")
+      );
+    },
+    replacement(content) {
+      return content;
+    },
+  });
+}