give out .json and .csv, not only .ndjson

lib.ts

@@ -17,6 +17,20 @@ export const thIgnore = [
 	"bpmkeytracker",
 ]
 
+export function jsonToCsv(data: unknown|unknown[]) {
+  const arr = Array.isArray(data) ? data : [data];
+  const headers = [...new Set(arr.flatMap(o => Object.keys(o)))];
+
+  const escape = (v: string )=>
+    `"${String(v ?? "").replace(/"/g, '""')}"`;
+
+  const rows = arr.map(o =>
+    headers.map(h => escape(o[h])).join(",")
+  );
+
+  return [headers.join(","), ...rows].join("\n");
+}
+
 export enum TripleBool {
   MOSTLY = 2,
   YES = 1,