chore: add Cisco to ADOPTERS.md (#5159)

- Add Cisco.com to the ADOPTERS.md

Signed-off-by: Sri Aradhyula <sraradhy@cisco.com>

ADOPTERS.md

@@ -3,6 +3,7 @@
 <!-- Add yourself here if you are using ESO in your company or your project! -->
 
 - [Amadeus](https://amadeus.com/)
+- [Cisco](https://www.cisco.com/)
 - [Codefresh](https://codefresh.io/)
 - [Container Solutions](http://container-solutions.com/)
 - [DaangnPay](https://www.daangnpay.com/)