Dehelmify, and install Crossplane via Jsonnet

Need to remove `Chart.yaml` so that Argo doesn't try to treat
`app-of-apps/` as a Helm application (because that would stop it from
using Jsonnet parsing).

app-of-apps/Chart.yaml

@@ -1,7 +0,0 @@
-apiVersion: v2
-name: jackjack-app-of-apps
-description: App-of-apps for deployment to Homelab
-
-type: application
-version: 0.1.0
-appVersion: "0.1.0"

app-of-apps/app-definitions.libsonnet

@@ -0,0 +1,35 @@
+{
+    helmApplication(
+        name,
+        sourceRepoUrl,
+        sourceChart,
+        sourceTargetRevision,
+        namespace="") ::
+    {
+        apiVersion: "argoproj.io/v1alpha1",
+        kind: "Application",
+        metadata: {
+            name: name,
+            namespace: "argo",
+            finalizers: ["resources-finalizer.argocd.argoproj.io"]
+        },
+        spec: {
+            project: "default",
+            source: {
+                chart: sourceChart,
+                repoURL: sourceRepoUrl,
+                targetRevision: sourceTargetRevision
+            },
+            destination: {
+                server: "https://kubernetes.default.svc",
+                namespace: if namespace == "" then name else namespace
+            },
+            syncPolicy: {
+                automated: {
+                    prune: true
+                },
+                syncOptions: ["CreateNamespace=true"]
+            }
+        }
+    }
+}

app-of-apps/crossplane.jsonnet

@@ -0,0 +1,10 @@
+// https://docs.crossplane.io/v1.15/software/install/#installed-deployments
+local appDef = import './app-definitions.libsonnet';
+
+appDef.helmApplication(
+  name="crossplane",
+  sourceRepoUrl="https://charts.crossplane.io/stable",
+  sourceChart="crossplane",
+  sourceTargetRevision="1.15.0",
+  namespace="crossplane-system"
+)