chore: Move editor into codebase (#2930)

shared/editor/queries/getParentListItem.ts

@@ -0,0 +1,14 @@
+import { Node } from "prosemirror-model";
+import { EditorState } from "prosemirror-state";
+
+export default function getParentListItem(
+  state: EditorState
+): [Node, number] | void {
+  const $head = state.selection.$head;
+  for (let d = $head.depth; d > 0; d--) {
+    const node = $head.node(d);
+    if (["list_item", "checkbox_item"].includes(node.type.name)) {
+      return [node, $head.before(d)];
+    }
+  }
+}