chore: Update Gmail URL (#205)

* Gmail README: Fix URL

All the other quickstarts seemed to have the right links already

* Update gmail/quickstart/README.md

Thanks!

Co-authored-by: Vinay Vyas <[email protected]>

Co-authored-by: Vinay Vyas <[email protected]>

Author: PartMan7

gmail/quickstart/README.md

@@ -1,7 +1,7 @@
 # Gmail Node.js Quickstart
 
 Complete the steps described in the [quickstart instructions](
-https://developers.google.com/calendar/quickstart/nodejs), and in about five
+https://developers.google.com/gmail/api/quickstart/nodejs), and in about five
 minutes you'll have a simple Node.js command-line application that makes
 requests to the Gmail API.