k6: add examples, modify description (#4330)

pages/common/k6.md

@@ -1,6 +1,6 @@
 # k6
 
-> A modern load testing tool, using Go and JavaScript.
+> Open source load testing tool and SaaS for engineering teams.
 > More information: <https://k6.io>.
 
 - Run load test locally:
@@ -19,6 +19,14 @@
 
 `k6 run --out influxdb={{http://localhost:8086/k6db}} {{script.js}}`
 
+- Run load test locally and discard response bodies (significantly faster):
+
+`k6 run --discard-response-bodies {{script.js}}`
+
+- Run load test locally using the base javascript compatibility mode (significantly faster):
+
+`k6 run --compatibility-mode=base {{script.js}}`
+
 - Login to cloud service using secret token:
 
 `k6 login cloud --token {{secret}}`