Document Kind CI trigger phrases (#6258)

Signed-off-by: KMAnju-2021 <km074btcse18@igdtuw.ac.in>

CONTRIBUTING.md

@@ -183,13 +183,23 @@ Here are the trigger phrases for individual checks:
 * `/test-rancher-e2e`: Linux IPv4 e2e tests on Rancher clusters.
 * `/test-rancher-conformance`: Linux IPv4 conformance tests on Rancher clusters.
 * `/test-rancher-networkpolicy`: Linux IPv4 networkpolicy tests on Rancher clusters.
+* `/test-kind-ipv6-e2e`: Linux dual stack e2e tests on Kind cluster.
+* `/test-kind-ipv6-only-e2e`: Linux IPv6 only e2e tests on Kind cluster.
+* `/test-kind-conformance`: Linux IPv4 conformance tests on Kind cluster.
+* `/test-kind-ipv6-only-conformance`: Linux IPv6 only conformance tests on Kind cluster.
+* `/test-kind-ipv6-conformance`: Linux dual stack conformance tests on Kind cluster.
+* `/test-kind-networkpolicy`: Linux IPv4 networkpolicy tests on Kind cluster.
+* `/test-kind-ipv6-only-networkpolicy`: Linux IPv6 only networkpolicy tests on Kind cluster.
+* `/test-kind-ipv6-networkpolicy`: Linux dual stack networkpolicy tests on Kind cluster.
 
 Here are the trigger phrases for groups of checks:
 
 * `/test-all`: Linux IPv4 tests
 * `/test-windows-all`: Windows IPv4 tests, including e2e tests with proxyAll enabled. It also includes all containerd runtime based Windows tests since 1.10.0.
 * `/test-ipv6-all`: Linux dual stack tests
 * `/test-ipv6-only-all`: Linux IPv6 only tests
+* `/test-kind-ipv6-only-all`: Linux IPv6 only tests on Kind cluster.
+* `/test-kind-ipv6-all`: Linux dual stack tests on Kind cluster.
 
 Besides, you can skip a check with `/skip-*`, e.g. `/skip-e2e`: skip Linux IPv4
 e2e tests.