docs: add Automated Tests section to basic and basic_tunnel READMEs (#735)

Signed-off-by: An <aqnguyen96@gmail.com>

Author: aqn96

exercises/basic/README.md

@@ -189,6 +189,12 @@ make stop
 Congratulations, your implementation works! Move onto the next assignment
 [Basic Tunneling](../basic_tunnel)
 
+## Automated Tests
+
+These tests are maintained to support CI/CD and help contributors verify 
+that the solution continues to work correctly across changes. PTF tests 
+are located in the `ptf/` directory and run against the solution program.
+
 ## Relevant Documentation
 
 The documentation for P4_16 and P4Runtime is available [here](https://p4.org/specifications/)

exercises/basic_tunnel/README.md

@@ -193,6 +193,12 @@ make stop
 Congratulations, your implementation works! Move onto the next assignment
 [p4runtime](../p4runtime)!
 
+## Automated Tests
+
+These tests are maintained to support CI/CD and help contributors verify 
+that the solution continues to work correctly across changes. PTF tests 
+are located in the `ptf/` directory and run against the solution program.
+
 ## Relevant Documentation
 
 Documentation on the Usage of Gateway (gw) and ARP Commands in topology.json is [here](https://github.com/p4lang/tutorials/tree/master/exercises/basic#the-use-of-gateway-gw-and-arp-commands-in-topologyjson)