added Vercel link to READMEs

dailyjs/basic-call/README.md

@@ -2,6 +2,8 @@
 
 ![Basic Call](./image.png)
 
+**[See it in action here ➡️](https://dailyjs-basic-call.vercel.app)**
+
 ## What does this demo do?
 
 - Built on [NextJS](https://nextjs.org/)
@@ -43,3 +45,7 @@ Abstraction hook that manages Daily call state and error handling
 
 **[ParticipantProvider.js](../shared/contexts/ParticipantProvider.js)**
 Manages participant state and abstracts common selectors / derived data
+
+## Deploy your own on Vercel
+
+[![Deploy with Vercel](https://vercel.com/button)](https://vercel.com/new/git/external?repository-url=https%3A%2F%2Fgithub.com%2Fvercel%2Fnext.js%2Ftree%2Fcanary%2Fexamples%2Fhello-world&env=DAILY_DOMAIN,DAILY_API_KEY&envDescription=Your%20Daily%20domain%20and%20API%20key%20can%20be%20found%20on%20your%20account%20dashboard&envLink=https%3A%2F%2Fdashboard.daily.co&project-name=daily-examples&repo-name=daily-examples)

dailyjs/basic-call/pages/api/token.js

@@ -21,7 +21,9 @@ export default async function handler(req, res) {
     };
 
     const dailyRes = await fetch(
-      `${process.env.DAILY_REST_DOMAIN}/meeting-tokens`,
+      `${
+        process.env.DAILY_REST_DOMAIN || 'https://api.daily.co/v1'
+      }/meeting-tokens`,
       options
     );