docs: add "Enterprise Support" to README

Readme.md

@@ -245,6 +245,12 @@ function awesomeAPI(foo, bar, callback) {
 
 People who use typical node.js style callbacks will be able to just pass a callback and get the expected behavior.  The enlightened people can not pass a callback and will get awesome promises.
 
+## Enterprise Support
+
+Available as part of the Tidelift Subscription
+
+The maintainers of promise and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source dependencies you use to build your applications. Save time, reduce risk, and improve code health, while paying the maintainers of the exact dependencies you use. [Learn more.](https://tidelift.com/subscription/pkg/npm-promise?utm_source=npm-promise&utm_medium=referral&utm_campaign=enterprise&utm_term=repo)
+
 ## License
 
   MIT