Add types and validation (#3)

src/types.ts

@@ -0,0 +1,5 @@
+export interface Directive {
+  text: string;
+  timestamp?: Date;
+  source: string;
+}

src/validate.ts

@@ -0,0 +1,5 @@
+import type { Directive } from "./types";
+
+export function validate(d: Directive): boolean {
+  return d.text.length > 0 && d.source.length > 0;
+}