Adding Adopters for CLO Monitor requirement [skip ci]

Adding link to Who Uses NATS on nats.io to fulfill CLO monitor requirement.

Author: gcolliso

README.md

@@ -53,6 +53,10 @@ If you are interested in contributing to NATS, read about our...
 
 The NATS product roadmap can be found [here](https://nats.io/about/#roadmap).
 
+## Adopters
+
+Who uses NATS? See our [list of users](https://nats.io/#who-uses-nats) on [https://nats.io](https://nats.io).
+
 ## Security
 
 ### Security Audit