Update docs/clustering/k8s.md
Update docs/clustering/k8s.md

add json

Co-Authored-By: godber <87211aa7e12f2c3c057fc7946f9753eed426e153@uberhip.com>
terascope/teraslice,terascope/teraslice,terascope/teraslice,terascope/teraslice