basic infrastructure for "relation map" note type

src/public/javascripts/services/note_detail_relation_map.js

@@ -0,0 +1,15 @@
+import server from "./server.js";
+import noteDetailService from "./note_detail.js";
+
+const $noteDetailRelationMap = $("#note-detail-relation-map");
+
+async function render() {
+    $noteDetailRelationMap.show();
+}
+
+export default {
+    show: render,
+    getContent: () => "",
+    focus: () => null,
+    onNoteChange: () => null
+}