feat: init deploy-gke Container Action (#2)

This commit inits the deploy-gke container action. It utlizes the
gke-deploy CLI image to deploy an existing image to a GKE cluster.

The integration test, documentation and CI setup are included within
this initial commit.

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Signed-off-by: JeromeJu <[email protected]>

entrypoint.sh

@@ -1,3 +1,5 @@
+#!/bin/sh -l
+
 # Copyright 2024 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -12,8 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-#!/bin/sh -l
-
 gha_version="0.1.0"
 
 image="$1"