Add test for kube-gcp basic step

Signed-off-by: Tom Chauveau <tom.chauveau@epitech.eu>

docs/learn/tests/kube-gcp/basic/todoapp.cue

@@ -0,0 +1,16 @@
+package main
+
+import (
+	"alpha.dagger.io/dagger"
+	"alpha.dagger.io/kubernetes"
+)
+
+// input: kubernetes objects directory to deploy to
+// set with `dagger input dir manifest ./k8s -e kube`
+manifest: dagger.#Artifact & dagger.#Input
+
+// Deploy the manifest to a kubernetes cluster
+todoApp: kubernetes.#Resources & {
+	"kubeconfig": kubeconfig
+	source:       manifest
+}