feat: add devcontainer (#446)

.devcontainer.json

@@ -0,0 +1,37 @@
+{
+  "name": "terraform-provider-argocd",
+  // officiall MS template from https://github.com/devcontainers/templates/tree/main/src/go
+  "image": "mcr.microsoft.com/devcontainers/go:1.21-bookworm",
+  "features": {
+    // https://github.com/devcontainers/features/tree/main/src/docker-in-docker
+    "ghcr.io/devcontainers/features/docker-in-docker:2": {
+      "enableNonRootDocker": "false",
+      "disableIp6tables": true // experienced issues with missing chains in ip6tables when creating kind clusters
+    },
+    // https://github.com/devcontainers/features/tree/main/src/terraform
+    "ghcr.io/devcontainers/features/terraform:1": {
+      "version": "1.9.7" // omit for latest
+    },
+    // https://github.com/mpriscella/features/tree/main/src/kind
+    "ghcr.io/mpriscella/features/kind:1": {
+      "version": "v0.20.0" // omit for latest
+    },
+    // https://github.com/devcontainers/features/tree/main/src/kubectl-helm-minikube
+    "ghcr.io/devcontainers/features/kubectl-helm-minikube:1": {
+      "version": "1.27.11"
+    },
+    // https://github.com/rio/features/tree/main/src/kustomize
+    "ghcr.io/rio/features/kustomize:1": {},
+    // https://github.com/guiyomh/features/blob/main/src/goreleaser
+    "ghcr.io/guiyomh/features/goreleaser:0": {},
+    // https://github.com/audacioustux/devcontainers/tree/main/src/argo
+    "ghcr.io/audacioustux/devcontainers/argo:1": {
+      "argocd": "2.8.13" // omit if empty
+    }
+  },
+  "forwardPorts": [
+    8080 // the "hard-coded" port for forwarded argo-cd"
+  ],
+  // Use 'postCreateCommand' to run commands after the container is created.
+  "postCreateCommand": "scripts/testacc_prepare_env.sh" // pre-create the kind cluster with argocd installed
+}