Add service.

src/lib/debounce.ts

@@ -0,0 +1,14 @@
+export class Debouncer {
+	last = 0
+
+	public constructor(
+		public timeout: number,
+	) {}
+
+	public should_skip() {
+		const now = Date.now()
+		const delay = now - this.last
+		this.last = now
+		return (delay < this.timeout)
+	}
+}