Deploy CRD as a pre-install hook

**What**
Using `lachlanevenson/k8s-kubectl`, which appears to be the most popular, off the shelf container with `kubectl` applied, run a job to apply the `workflow` crd.

**Why**
CRD is not, and cannot, be parameterized with release and so attempting to deploy as a regular template causes failures when installing subsequent releases.

charts/argo/templates/_workflow-crd.json

@@ -0,0 +1,19 @@
+{{- define "workflow-crd-json" }}
+{
+  "apiVersion": "apiextensions.k8s.io/v1beta1",
+  "kind": "CustomResourceDefinition",
+  "metadata": {
+    "name": "workflows.argoproj.io"
+  },
+  "spec": {
+    "group": "argoproj.io",
+    "names": {
+      "kind": "Workflow",
+      "plural": "workflows",
+      "shortNames": ["wf"]
+    },
+    "scope": "Namespaced",
+    "version": "v1alpha1"
+  }
+}
+{{- end}}

charts/argo/templates/apply-workflow-crd-job.yaml

@@ -0,0 +1,18 @@
+apiVersion: batch/v1
+kind: Job
+metadata:
+  name: {{ .Release.Name }}-apply-workflow-crd
+  annotations:
+    helm.sh/hook: pre-install
+    helm.sh/hook-delete-policy: hook-succeeded
+spec:
+  backoffLimit: 5
+  activeDeadlineSeconds: 100
+  template:
+    spec:
+      containers:
+      - name: kubectl-apply
+        image: lachlanevenson/k8s-kubectl
+        command: ["/bin/sh"]
+        args: ["-c", 'echo ''{{- include "workflow-crd-json" .}}'' | kubectl apply -f -']
+      restartPolicy: Never

charts/argo/templates/workflow-crd.yaml

@@ -1,13 +0,0 @@
-apiVersion: apiextensions.k8s.io/v1beta1
-kind: CustomResourceDefinition
-metadata:
-  name: workflows.argoproj.io
-spec:
-  group: argoproj.io
-  names:
-    kind: Workflow
-    plural: workflows
-    shortNames:
-    - wf
-  scope: Namespaced
-  version: v1alpha1