update to new workspace API keys setup

Author: steven-tey

.env.example

@@ -1,3 +1,6 @@
+# Get your own Dub API key: https://dub.co/docs/api-reference/tokens
+DUB_API_KEY=
+
 # GitHub
 AUTH_GITHUB_ID=
 AUTH_GITHUB_SECRET=

lib/dub.ts

@@ -4,9 +4,7 @@ import { Link } from "@prisma/client";
 import { Dub } from "dub";
 import { getUrlWithRef } from "./utils";
 
-export const dub = new Dub({
-  workspaceId: "ws_clv9jxuxp0006gpq847kwrcwj",
-});
+export const dub = new Dub();
 
 export async function shortenAndCreateLink({
   url,